diff --git a/browser_tests/fixtures/selectors.ts b/browser_tests/fixtures/selectors.ts
index 0fecdbeefe9..765ba31961f 100644
--- a/browser_tests/fixtures/selectors.ts
+++ b/browser_tests/fixtures/selectors.ts
@@ -28,10 +28,15 @@ export const TestIds = {
     settingsTabAbout: 'settings-tab-about',
     confirm: 'confirm-dialog',
     errorOverlay: 'error-overlay',
+    errorOverlaySeeErrors: 'error-overlay-see-errors',
     runtimeErrorPanel: 'runtime-error-panel',
     missingNodeCard: 'missing-node-card',
+    errorCardFindOnGithub: 'error-card-find-on-github',
+    errorCardCopy: 'error-card-copy',
     about: 'about-panel',
-    whatsNewSection: 'whats-new-section'
+    whatsNewSection: 'whats-new-section',
+    missingNodePacksGroup: 'error-group-missing-node',
+    missingModelsGroup: 'error-group-missing-model'
   },
   keybindings: {
     presetMenu: 'keybinding-preset-menu'
@@ -76,6 +81,10 @@ export const TestIds = {
   },
   user: {
     currentUserIndicator: 'current-user-indicator'
+  },
+  errors: {
+    imageLoadError: 'error-loading-image',
+    videoLoadError: 'error-loading-video'
   }
 } as const
 
@@ -101,3 +110,4 @@ export type TestIdValue =
       (id: string) => string
     >
   | (typeof TestIds.user)[keyof typeof TestIds.user]
+  | (typeof TestIds.errors)[keyof typeof TestIds.errors]
diff --git a/browser_tests/tests/dialog.spec.ts b/browser_tests/tests/dialog.spec.ts
index 03111e0896b..809c44d64cf 100644
--- a/browser_tests/tests/dialog.spec.ts
+++ b/browser_tests/tests/dialog.spec.ts
@@ -28,7 +28,7 @@ test.describe('Missing nodes in Error Overlay', { tag: '@ui' }, () => {
     )
     await expect(errorOverlay).toBeVisible()
 
-    const missingNodesTitle = comfyPage.page.getByText(/Missing Node Packs/)
+    const missingNodesTitle = errorOverlay.getByText(/Missing Node Packs/)
     await expect(missingNodesTitle).toBeVisible()
   })
 
@@ -42,11 +42,13 @@ test.describe('Missing nodes in Error Overlay', { tag: '@ui' }, () => {
     )
     await expect(errorOverlay).toBeVisible()
 
-    const missingNodesTitle = comfyPage.page.getByText(/Missing Node Packs/)
+    const missingNodesTitle = errorOverlay.getByText(/Missing Node Packs/)
     await expect(missingNodesTitle).toBeVisible()
 
     // Click "See Errors" to open the errors tab and verify subgraph node content
-    await errorOverlay.getByRole('button', { name: 'See Errors' }).click()
+    await errorOverlay
+      .getByTestId(TestIds.dialogs.errorOverlaySeeErrors)
+      .click()
     await expect(errorOverlay).not.toBeVisible()
 
     const missingNodeCard = comfyPage.page.getByTestId(
@@ -75,7 +77,9 @@ test.describe('Missing nodes in Error Overlay', { tag: '@ui' }, () => {
     await expect(errorOverlay).toBeVisible()
 
     // Click "See Errors" to open the right side panel errors tab
-    await errorOverlay.getByRole('button', { name: 'See Errors' }).click()
+    await errorOverlay
+      .getByTestId(TestIds.dialogs.errorOverlaySeeErrors)
+      .click()
     await expect(errorOverlay).not.toBeVisible()
 
     // Verify MissingNodeCard is rendered in the errors tab
@@ -165,17 +169,19 @@ test.describe('Error actions in Errors Tab', { tag: '@ui' }, () => {
       TestIds.dialogs.errorOverlay
     )
     await expect(errorOverlay).toBeVisible()
-    await errorOverlay.getByRole('button', { name: 'See Errors' }).click()
+    await errorOverlay
+      .getByTestId(TestIds.dialogs.errorOverlaySeeErrors)
+      .click()
     await expect(errorOverlay).not.toBeVisible()
 
     // Verify Find on GitHub button is present in the error card
-    const findOnGithubButton = comfyPage.page.getByRole('button', {
-      name: 'Find on GitHub'
-    })
+    const findOnGithubButton = comfyPage.page.getByTestId(
+      TestIds.dialogs.errorCardFindOnGithub
+    )
     await expect(findOnGithubButton).toBeVisible()
 
     // Verify Copy button is present in the error card
-    const copyButton = comfyPage.page.getByRole('button', { name: 'Copy' })
+    const copyButton = comfyPage.page.getByTestId(TestIds.dialogs.errorCardCopy)
     await expect(copyButton).toBeVisible()
   })
 })
@@ -204,7 +210,7 @@ test.describe('Missing models in Error Tab', () => {
     )
     await expect(errorOverlay).toBeVisible()
 
-    const missingModelsTitle = comfyPage.page.getByText(/Missing Models/)
+    const missingModelsTitle = errorOverlay.getByText(/Missing Models/)
     await expect(missingModelsTitle).toBeVisible()
   })
 
@@ -220,7 +226,7 @@ test.describe('Missing models in Error Tab', () => {
     )
     await expect(errorOverlay).toBeVisible()
 
-    const missingModelsTitle = comfyPage.page.getByText(/Missing Models/)
+    const missingModelsTitle = errorOverlay.getByText(/Missing Models/)
     await expect(missingModelsTitle).toBeVisible()
   })
 
@@ -231,13 +237,10 @@ test.describe('Missing models in Error Tab', () => {
       'missing/model_metadata_widget_mismatch'
     )
 
-    const missingModelsTitle = comfyPage.page.getByText(/Missing Models/)
-    await expect(missingModelsTitle).not.toBeVisible()
-
-    const errorOverlay = comfyPage.page.getByTestId(
-      TestIds.dialogs.errorOverlay
-    )
-    await expect(errorOverlay).not.toBeVisible()
+    await expect(
+      comfyPage.page.getByTestId(TestIds.dialogs.errorOverlay)
+    ).not.toBeVisible()
+    await expect(comfyPage.page.getByText(/Missing Models/)).not.toBeVisible()
   })
 
   // Flaky test after parallelization
diff --git a/browser_tests/tests/vueNodes/widgets/load/uploadWidgets.spec.ts b/browser_tests/tests/vueNodes/widgets/load/uploadWidgets.spec.ts
index 077e56a4aa1..0998c3eacb1 100644
--- a/browser_tests/tests/vueNodes/widgets/load/uploadWidgets.spec.ts
+++ b/browser_tests/tests/vueNodes/widgets/load/uploadWidgets.spec.ts
@@ -2,6 +2,7 @@ import {
   comfyExpect as expect,
   comfyPageFixture as test
 } from '../../../../fixtures/ComfyPage'
+import { TestIds } from '../../../../fixtures/selectors'
 
 test.describe('Vue Upload Widgets', () => {
   test.beforeEach(async ({ comfyPage }) => {
@@ -19,10 +20,14 @@ test.describe('Vue Upload Widgets', () => {
     ).not.toBeVisible()
 
     await expect
-      .poll(() => comfyPage.page.getByText('Error loading image').count())
+      .poll(() =>
+        comfyPage.page.getByTestId(TestIds.errors.imageLoadError).count()
+      )
       .toBeGreaterThan(0)
     await expect
-      .poll(() => comfyPage.page.getByText('Error loading video').count())
+      .poll(() =>
+        comfyPage.page.getByTestId(TestIds.errors.videoLoadError).count()
+      )
       .toBeGreaterThan(0)
   })
 })
diff --git a/src/components/dialog/content/error/FindIssueButton.vue b/src/components/dialog/content/error/FindIssueButton.vue
index 767202251f5..7ec89ebc86a 100644
--- a/src/components/dialog/content/error/FindIssueButton.vue
+++ b/src/components/dialog/content/error/FindIssueButton.vue
@@ -19,10 +19,7 @@ const props = defineProps<{
 
 const queryString = computed(() => props.errorMessage + ' is:issue')
 
-/**
- * Open GitHub issues search and track telemetry.
- */
-const openGitHubIssues = () => {
+function openGitHubIssues() {
   useTelemetry()?.trackUiButtonClicked({
     button_id: 'error_dialog_find_existing_issues_clicked'
   })
diff --git a/src/components/error/ErrorOverlay.vue b/src/components/error/ErrorOverlay.vue
index be599a39958..f5d74c2285a 100644
--- a/src/components/error/ErrorOverlay.vue
+++ b/src/components/error/ErrorOverlay.vue
@@ -49,7 +49,12 @@
           <Button variant="muted-textonly" size="unset" @click="dismiss">
             {{ t('g.dismiss') }}
           </Button>
-          <Button variant="secondary" size="lg" @click="seeErrors">
+          <Button
+            variant="secondary"
+            size="lg"
+            data-testid="error-overlay-see-errors"
+            @click="seeErrors"
+          >
             {{
               appMode ? t('linearMode.error.goto') : t('errorOverlay.seeErrors')
             }}
diff --git a/src/components/rightSidePanel/RightSidePanel.vue b/src/components/rightSidePanel/RightSidePanel.vue
index 38a9c663e99..af24d79536c 100644
--- a/src/components/rightSidePanel/RightSidePanel.vue
+++ b/src/components/rightSidePanel/RightSidePanel.vue
@@ -9,12 +9,15 @@ import TabList from '@/components/tab/TabList.vue'
 import Button from '@/components/ui/button/Button.vue'
 import { useGraphHierarchy } from '@/composables/graph/useGraphHierarchy'
 import { st } from '@/i18n'
+import { app } from '@/scripts/app'
+import { getActiveGraphNodeIds } from '@/utils/graphTraversalUtil'
 import { SubgraphNode } from '@/lib/litegraph/src/litegraph'
 import type { LGraphNode } from '@/lib/litegraph/src/litegraph'
 import { useSettingStore } from '@/platform/settings/settingStore'
 import { useCanvasStore } from '@/renderer/core/canvas/canvasStore'
 import { useMissingModelStore } from '@/platform/missingModel/missingModelStore'
 import { useExecutionErrorStore } from '@/stores/executionErrorStore'
+import { useMissingNodesErrorStore } from '@/platform/nodeReplacement/missingNodesErrorStore'
 import { useRightSidePanelStore } from '@/stores/workspace/rightSidePanelStore'
 import type { RightSidePanelTab } from '@/stores/workspace/rightSidePanelStore'
 import { resolveNodeDisplayName } from '@/utils/nodeTitleUtil'
@@ -38,12 +41,21 @@ import TabErrors from './errors/TabErrors.vue'
 const canvasStore = useCanvasStore()
 const executionErrorStore = useExecutionErrorStore()
 const missingModelStore = useMissingModelStore()
+const missingNodesErrorStore = useMissingNodesErrorStore()
 const rightSidePanelStore = useRightSidePanelStore()
 const settingStore = useSettingStore()
 const { t } = useI18n()
 
-const { hasAnyError, allErrorExecutionIds, activeMissingNodeGraphIds } =
-  storeToRefs(executionErrorStore)
+const { hasAnyError, allErrorExecutionIds } = storeToRefs(executionErrorStore)
+
+const activeMissingNodeGraphIds = computed<Set<string>>(() => {
+  if (!app.isGraphReady) return new Set()
+  return getActiveGraphNodeIds(
+    app.rootGraph,
+    canvasStore.currentGraph ?? app.rootGraph,
+    missingNodesErrorStore.missingAncestorExecutionIds
+  )
+})
 
 const { activeMissingModelGraphIds } = storeToRefs(missingModelStore)
 
diff --git a/src/components/rightSidePanel/errors/ErrorNodeCard.test.ts b/src/components/rightSidePanel/errors/ErrorNodeCard.test.ts
index 2569437add8..7b58195fa8e 100644
--- a/src/components/rightSidePanel/errors/ErrorNodeCard.test.ts
+++ b/src/components/rightSidePanel/errors/ErrorNodeCard.test.ts
@@ -237,6 +237,11 @@ describe('ErrorNodeCard.vue', () => {
 
     // Report is still generated with fallback log message
     expect(mockGenerateErrorReport).toHaveBeenCalledOnce()
+    expect(mockGenerateErrorReport).toHaveBeenCalledWith(
+      expect.objectContaining({
+        serverLogs: 'Failed to retrieve server logs'
+      })
+    )
     expect(wrapper.text()).toContain('ComfyUI Error Report')
   })
 
diff --git a/src/components/rightSidePanel/errors/ErrorNodeCard.vue b/src/components/rightSidePanel/errors/ErrorNodeCard.vue
index dc17c890ebb..0119df11bee 100644
--- a/src/components/rightSidePanel/errors/ErrorNodeCard.vue
+++ b/src/components/rightSidePanel/errors/ErrorNodeCard.vue
@@ -90,6 +90,7 @@
               variant="secondary"
               size="sm"
               class="h-8 w-2/3 justify-center gap-1 rounded-lg text-xs"
+              data-testid="error-card-find-on-github"
               @click="handleCheckGithub(error)"
             >
               {{ t('g.findOnGithub') }}
@@ -99,6 +100,7 @@
               variant="secondary"
               size="sm"
               class="h-8 w-1/3 justify-center gap-1 rounded-lg text-xs"
+              data-testid="error-card-copy"
               @click="handleCopyError(idx)"
             >
               {{ t('g.copy') }}
@@ -125,12 +127,10 @@
 import { useI18n } from 'vue-i18n'
 
 import Button from '@/components/ui/button/Button.vue'
-import { useExternalLink } from '@/composables/useExternalLink'
-import { useTelemetry } from '@/platform/telemetry'
-import { useCommandStore } from '@/stores/commandStore'
 import { cn } from '@/utils/tailwindUtil'
 
 import type { ErrorCardData, ErrorItem } from './types'
+import { useErrorActions } from './useErrorActions'
 import { useErrorReport } from './useErrorReport'
 
 const {
@@ -154,10 +154,8 @@ const emit = defineEmits<{
 }>()
 
 const { t } = useI18n()
-const telemetry = useTelemetry()
-const { staticUrls } = useExternalLink()
-const commandStore = useCommandStore()
 const { displayedDetailsMap } = useErrorReport(() => card)
+const { findOnGitHub, contactSupport: handleGetHelp } = useErrorActions()
 
 function handleLocateNode() {
   if (card.nodeId) {
@@ -178,23 +176,6 @@ function handleCopyError(idx: number) {
 }
 
 function handleCheckGithub(error: ErrorItem) {
-  telemetry?.trackUiButtonClicked({
-    button_id: 'error_tab_find_existing_issues_clicked'
-  })
-  const query = encodeURIComponent(error.message + ' is:issue')
-  window.open(
-    `${staticUrls.githubIssues}?q=${query}`,
-    '_blank',
-    'noopener,noreferrer'
-  )
-}
-
-function handleGetHelp() {
-  telemetry?.trackHelpResourceClicked({
-    resource_type: 'help_feedback',
-    is_external: true,
-    source: 'error_dialog'
-  })
-  commandStore.execute('Comfy.ContactSupport')
+  findOnGitHub(error.message)
 }
 </script>
diff --git a/src/components/rightSidePanel/errors/MissingNodeCard.test.ts b/src/components/rightSidePanel/errors/MissingNodeCard.test.ts
index 5af164aeffd..d9a55d21c36 100644
--- a/src/components/rightSidePanel/errors/MissingNodeCard.test.ts
+++ b/src/components/rightSidePanel/errors/MissingNodeCard.test.ts
@@ -1,7 +1,5 @@
 import { mount } from '@vue/test-utils'
 import { createTestingPinia } from '@pinia/testing'
-import PrimeVue from 'primevue/config'
-import { ref } from 'vue'
 import { beforeEach, describe, expect, it, vi } from 'vitest'
 import { createI18n } from 'vue-i18n'
 
@@ -42,23 +40,25 @@ vi.mock('@/stores/systemStatsStore', () => ({
   })
 }))
 
-const mockApplyChanges = vi.fn()
-const mockIsRestarting = ref(false)
+const mockApplyChanges = vi.hoisted(() => vi.fn())
+const mockIsRestarting = vi.hoisted(() => ({ value: false }))
 vi.mock('@/workbench/extensions/manager/composables/useApplyChanges', () => ({
   useApplyChanges: () => ({
-    isRestarting: mockIsRestarting,
+    get isRestarting() {
+      return mockIsRestarting.value
+    },
     applyChanges: mockApplyChanges
   })
 }))
 
-const mockIsPackInstalled = vi.fn(() => false)
+const mockIsPackInstalled = vi.hoisted(() => vi.fn(() => false))
 vi.mock('@/workbench/extensions/manager/stores/comfyManagerStore', () => ({
   useComfyManagerStore: () => ({
     isPackInstalled: mockIsPackInstalled
   })
 }))
 
-const mockShouldShowManagerButtons = { value: false }
+const mockShouldShowManagerButtons = vi.hoisted(() => ({ value: false }))
 vi.mock('@/workbench/extensions/manager/composables/useManagerState', () => ({
   useManagerState: () => ({
     shouldShowManagerButtons: mockShouldShowManagerButtons
@@ -128,7 +128,7 @@ function mountCard(
       ...props
     },
     global: {
-      plugins: [createTestingPinia({ createSpy: vi.fn }), PrimeVue, i18n],
+      plugins: [createTestingPinia({ createSpy: vi.fn }), i18n],
       stubs: {
         DotSpinner: { template: '<span role="status" aria-label="loading" />' }
       }
diff --git a/src/components/rightSidePanel/errors/TabErrors.test.ts b/src/components/rightSidePanel/errors/TabErrors.test.ts
index 640648f3c2f..b64b63727db 100644
--- a/src/components/rightSidePanel/errors/TabErrors.test.ts
+++ b/src/components/rightSidePanel/errors/TabErrors.test.ts
@@ -209,12 +209,9 @@ describe('TabErrors.vue', () => {
       }
     })
 
-    // Find the copy button by text (rendered inside ErrorNodeCard)
-    const copyButton = wrapper
-      .findAll('button')
-      .find((btn) => btn.text().includes('Copy'))
-    expect(copyButton).toBeTruthy()
-    await copyButton!.trigger('click')
+    const copyButton = wrapper.find('[data-testid="error-card-copy"]')
+    expect(copyButton.exists()).toBe(true)
+    await copyButton.trigger('click')
 
     expect(mockCopy).toHaveBeenCalledWith('Test message\n\nTest details')
   })
@@ -245,5 +242,9 @@ describe('TabErrors.vue', () => {
     // Should render in the dedicated runtime error panel, not inside accordion
     const runtimePanel = wrapper.find('[data-testid="runtime-error-panel"]')
     expect(runtimePanel.exists()).toBe(true)
+    // Verify the error message appears exactly once (not duplicated in accordion)
+    expect(
+      wrapper.text().match(/RuntimeError: Out of memory/g) ?? []
+    ).toHaveLength(1)
   })
 })
diff --git a/src/components/rightSidePanel/errors/TabErrors.vue b/src/components/rightSidePanel/errors/TabErrors.vue
index b7ad445eaed..cedb3f8f24a 100644
--- a/src/components/rightSidePanel/errors/TabErrors.vue
+++ b/src/components/rightSidePanel/errors/TabErrors.vue
@@ -53,6 +53,7 @@
         <PropertiesAccordionItem
           v-for="group in filteredGroups"
           :key="group.title"
+          :data-testid="'error-group-' + group.type.replaceAll('_', '-')"
           :collapse="isSectionCollapsed(group.title) && !isSearching"
           class="border-b border-interface-stroke"
           :size="getGroupSize(group)"
@@ -209,12 +210,9 @@
 import { computed, ref, watch } from 'vue'
 import { useI18n } from 'vue-i18n'
 
-import { useCommandStore } from '@/stores/commandStore'
 import { useCopyToClipboard } from '@/composables/useCopyToClipboard'
 import { useFocusNode } from '@/composables/canvas/useFocusNode'
-import { useExternalLink } from '@/composables/useExternalLink'
 import { useSettingStore } from '@/platform/settings/settingStore'
-import { useTelemetry } from '@/platform/telemetry'
 import { useRightSidePanelStore } from '@/stores/workspace/rightSidePanelStore'
 import { useManagerState } from '@/workbench/extensions/manager/composables/useManagerState'
 import { ManagerTab } from '@/workbench/extensions/manager/types/comfyManagerTypes'
@@ -238,6 +236,7 @@ import Button from '@/components/ui/button/Button.vue'
 import DotSpinner from '@/components/common/DotSpinner.vue'
 import { usePackInstall } from '@/workbench/extensions/manager/composables/nodePack/usePackInstall'
 import { useMissingNodes } from '@/workbench/extensions/manager/composables/nodePack/useMissingNodes'
+import { useErrorActions } from './useErrorActions'
 import { useErrorGroups } from './useErrorGroups'
 import type { SwapNodeGroup } from './useErrorGroups'
 import type { ErrorGroup } from './types'
@@ -246,7 +245,7 @@ import { useNodeReplacement } from '@/platform/nodeReplacement/useNodeReplacemen
 const { t } = useI18n()
 const { copyToClipboard } = useCopyToClipboard()
 const { focusNode, enterSubgraph } = useFocusNode()
-const { staticUrls } = useExternalLink()
+const { openGitHubIssues, contactSupport } = useErrorActions()
 const settingStore = useSettingStore()
 const rightSidePanelStore = useRightSidePanelStore()
 const { shouldShowManagerButtons, shouldShowInstallButton, openManager } =
@@ -372,13 +371,13 @@ watch(
     if (!graphNodeId) return
     const prefix = `${graphNodeId}:`
     for (const group of allErrorGroups.value) {
-      const hasMatch =
-        group.type === 'execution' &&
-        group.cards.some(
-          (card) =>
-            card.graphNodeId === graphNodeId ||
-            (card.nodeId?.startsWith(prefix) ?? false)
-        )
+      if (group.type !== 'execution') continue
+
+      const hasMatch = group.cards.some(
+        (card) =>
+          card.graphNodeId === graphNodeId ||
+          (card.nodeId?.startsWith(prefix) ?? false)
+      )
       setSectionCollapsed(group.title, !hasMatch)
     }
     rightSidePanelStore.focusedErrorNodeId = null
@@ -418,20 +417,4 @@ function handleReplaceAll() {
 function handleEnterSubgraph(nodeId: string) {
   enterSubgraph(nodeId, errorNodeCache.value)
 }
-
-function openGitHubIssues() {
-  useTelemetry()?.trackUiButtonClicked({
-    button_id: 'error_tab_github_issues_clicked'
-  })
-  window.open(staticUrls.githubIssues, '_blank', 'noopener,noreferrer')
-}
-
-async function contactSupport() {
-  useTelemetry()?.trackHelpResourceClicked({
-    resource_type: 'help_feedback',
-    is_external: true,
-    source: 'error_dialog'
-  })
-  useCommandStore().execute('Comfy.ContactSupport')
-}
 </script>
diff --git a/src/components/rightSidePanel/errors/swapNodeGroups.test.ts b/src/components/rightSidePanel/errors/swapNodeGroups.test.ts
index de497e3cbca..4af142a3721 100644
--- a/src/components/rightSidePanel/errors/swapNodeGroups.test.ts
+++ b/src/components/rightSidePanel/errors/swapNodeGroups.test.ts
@@ -47,7 +47,7 @@ vi.mock('@/utils/executableGroupNodeDto', () => ({
   isGroupNode: vi.fn(() => false)
 }))
 
-import { useExecutionErrorStore } from '@/stores/executionErrorStore'
+import { useMissingNodesErrorStore } from '@/platform/nodeReplacement/missingNodesErrorStore'
 import { useErrorGroups } from './useErrorGroups'
 
 function makeMissingNodeType(
@@ -80,8 +80,7 @@ describe('swapNodeGroups computed', () => {
   })
 
   function getSwapNodeGroups(nodeTypes: MissingNodeType[]) {
-    const store = useExecutionErrorStore()
-    store.surfaceMissingNodes(nodeTypes)
+    useMissingNodesErrorStore().surfaceMissingNodes(nodeTypes)
 
     const searchQuery = ref('')
     const t = (key: string) => key
diff --git a/src/components/rightSidePanel/errors/useErrorActions.ts b/src/components/rightSidePanel/errors/useErrorActions.ts
new file mode 100644
index 00000000000..9cc1bade0cf
--- /dev/null
+++ b/src/components/rightSidePanel/errors/useErrorActions.ts
@@ -0,0 +1,39 @@
+import { useCommandStore } from '@/stores/commandStore'
+import { useExternalLink } from '@/composables/useExternalLink'
+import { useTelemetry } from '@/platform/telemetry'
+
+export function useErrorActions() {
+  const telemetry = useTelemetry()
+  const commandStore = useCommandStore()
+  const { staticUrls } = useExternalLink()
+
+  function openGitHubIssues() {
+    telemetry?.trackUiButtonClicked({
+      button_id: 'error_tab_github_issues_clicked'
+    })
+    window.open(staticUrls.githubIssues, '_blank', 'noopener,noreferrer')
+  }
+
+  function contactSupport() {
+    telemetry?.trackHelpResourceClicked({
+      resource_type: 'help_feedback',
+      is_external: true,
+      source: 'error_dialog'
+    })
+    void commandStore.execute('Comfy.ContactSupport')
+  }
+
+  function findOnGitHub(errorMessage: string) {
+    telemetry?.trackUiButtonClicked({
+      button_id: 'error_tab_find_existing_issues_clicked'
+    })
+    const query = encodeURIComponent(errorMessage + ' is:issue')
+    window.open(
+      `${staticUrls.githubIssues}?q=${query}`,
+      '_blank',
+      'noopener,noreferrer'
+    )
+  }
+
+  return { openGitHubIssues, contactSupport, findOnGitHub }
+}
diff --git a/src/components/rightSidePanel/errors/useErrorGroups.test.ts b/src/components/rightSidePanel/errors/useErrorGroups.test.ts
index f388221015b..3455badf8ff 100644
--- a/src/components/rightSidePanel/errors/useErrorGroups.test.ts
+++ b/src/components/rightSidePanel/errors/useErrorGroups.test.ts
@@ -58,6 +58,7 @@ vi.mock(
 )
 
 import { useExecutionErrorStore } from '@/stores/executionErrorStore'
+import { useMissingNodesErrorStore } from '@/platform/nodeReplacement/missingNodesErrorStore'
 import { useErrorGroups } from './useErrorGroups'
 
 function makeMissingNodeType(
@@ -126,8 +127,9 @@ describe('useErrorGroups', () => {
     })
 
     it('groups non-replaceable nodes by cnrId', async () => {
-      const { store, groups } = createErrorGroups()
-      store.setMissingNodeTypes([
+      const { groups } = createErrorGroups()
+      const missingNodesStore = useMissingNodesErrorStore()
+      missingNodesStore.setMissingNodeTypes([
         makeMissingNodeType('NodeA', { cnrId: 'pack-1' }),
         makeMissingNodeType('NodeB', { cnrId: 'pack-1', nodeId: '2' }),
         makeMissingNodeType('NodeC', { cnrId: 'pack-2', nodeId: '3' })
@@ -146,8 +148,9 @@ describe('useErrorGroups', () => {
     })
 
     it('excludes replaceable nodes from missingPackGroups', async () => {
-      const { store, groups } = createErrorGroups()
-      store.setMissingNodeTypes([
+      const { groups } = createErrorGroups()
+      const missingNodesStore = useMissingNodesErrorStore()
+      missingNodesStore.setMissingNodeTypes([
         makeMissingNodeType('OldNode', {
           isReplaceable: true,
           replacement: { new_node_id: 'NewNode' }
@@ -164,8 +167,9 @@ describe('useErrorGroups', () => {
     })
 
     it('groups nodes without cnrId under null packId', async () => {
-      const { store, groups } = createErrorGroups()
-      store.setMissingNodeTypes([
+      const { groups } = createErrorGroups()
+      const missingNodesStore = useMissingNodesErrorStore()
+      missingNodesStore.setMissingNodeTypes([
         makeMissingNodeType('UnknownNode', { nodeId: '1' }),
         makeMissingNodeType('AnotherUnknown', { nodeId: '2' })
       ])
@@ -177,8 +181,9 @@ describe('useErrorGroups', () => {
     })
 
     it('sorts groups alphabetically with null packId last', async () => {
-      const { store, groups } = createErrorGroups()
-      store.setMissingNodeTypes([
+      const { groups } = createErrorGroups()
+      const missingNodesStore = useMissingNodesErrorStore()
+      missingNodesStore.setMissingNodeTypes([
         makeMissingNodeType('NodeA', { cnrId: 'zebra-pack' }),
         makeMissingNodeType('NodeB', { nodeId: '2' }),
         makeMissingNodeType('NodeC', { cnrId: 'alpha-pack', nodeId: '3' })
@@ -190,8 +195,9 @@ describe('useErrorGroups', () => {
     })
 
     it('sorts nodeTypes within each group alphabetically by type then nodeId', async () => {
-      const { store, groups } = createErrorGroups()
-      store.setMissingNodeTypes([
+      const { groups } = createErrorGroups()
+      const missingNodesStore = useMissingNodesErrorStore()
+      missingNodesStore.setMissingNodeTypes([
         makeMissingNodeType('NodeB', { cnrId: 'pack-1', nodeId: '2' }),
         makeMissingNodeType('NodeA', { cnrId: 'pack-1', nodeId: '3' }),
         makeMissingNodeType('NodeA', { cnrId: 'pack-1', nodeId: '1' })
@@ -206,8 +212,9 @@ describe('useErrorGroups', () => {
     })
 
     it('handles string nodeType entries', async () => {
-      const { store, groups } = createErrorGroups()
-      store.setMissingNodeTypes([
+      const { groups } = createErrorGroups()
+      const missingNodesStore = useMissingNodesErrorStore()
+      missingNodesStore.setMissingNodeTypes([
         'StringGroupNode' as unknown as MissingNodeType
       ])
       await nextTick()
@@ -224,8 +231,9 @@ describe('useErrorGroups', () => {
     })
 
     it('includes missing_node group when missing nodes exist', async () => {
-      const { store, groups } = createErrorGroups()
-      store.setMissingNodeTypes([
+      const { groups } = createErrorGroups()
+      const missingNodesStore = useMissingNodesErrorStore()
+      missingNodesStore.setMissingNodeTypes([
         makeMissingNodeType('NodeA', { cnrId: 'pack-1' })
       ])
       await nextTick()
@@ -237,8 +245,9 @@ describe('useErrorGroups', () => {
     })
 
     it('includes swap_nodes group when replaceable nodes exist', async () => {
-      const { store, groups } = createErrorGroups()
-      store.setMissingNodeTypes([
+      const { groups } = createErrorGroups()
+      const missingNodesStore = useMissingNodesErrorStore()
+      missingNodesStore.setMissingNodeTypes([
         makeMissingNodeType('OldNode', {
           isReplaceable: true,
           replacement: { new_node_id: 'NewNode' }
@@ -253,8 +262,9 @@ describe('useErrorGroups', () => {
     })
 
     it('includes both swap_nodes and missing_node when both exist', async () => {
-      const { store, groups } = createErrorGroups()
-      store.setMissingNodeTypes([
+      const { groups } = createErrorGroups()
+      const missingNodesStore = useMissingNodesErrorStore()
+      missingNodesStore.setMissingNodeTypes([
         makeMissingNodeType('OldNode', {
           isReplaceable: true,
           replacement: { new_node_id: 'NewNode' }
@@ -272,8 +282,9 @@ describe('useErrorGroups', () => {
     })
 
     it('swap_nodes has lower priority than missing_node', async () => {
-      const { store, groups } = createErrorGroups()
-      store.setMissingNodeTypes([
+      const { groups } = createErrorGroups()
+      const missingNodesStore = useMissingNodesErrorStore()
+      missingNodesStore.setMissingNodeTypes([
         makeMissingNodeType('OldNode', {
           isReplaceable: true,
           replacement: { new_node_id: 'NewNode' }
@@ -533,13 +544,18 @@ describe('useErrorGroups', () => {
     })
 
     it('includes missing node group title as message', async () => {
-      const { store, groups } = createErrorGroups()
-      store.setMissingNodeTypes([
+      const { groups } = createErrorGroups()
+      const missingNodesStore = useMissingNodesErrorStore()
+      missingNodesStore.setMissingNodeTypes([
         makeMissingNodeType('NodeA', { cnrId: 'pack-1' })
       ])
       await nextTick()
 
-      expect(groups.groupedErrorMessages.value.length).toBeGreaterThan(0)
+      const missingGroup = groups.allErrorGroups.value.find(
+        (g) => g.type === 'missing_node'
+      )
+      expect(missingGroup).toBeDefined()
+      expect(groups.groupedErrorMessages.value).toContain(missingGroup!.title)
     })
   })
 
diff --git a/src/components/rightSidePanel/errors/useErrorGroups.ts b/src/components/rightSidePanel/errors/useErrorGroups.ts
index d8c4403f101..61d428efbec 100644
--- a/src/components/rightSidePanel/errors/useErrorGroups.ts
+++ b/src/components/rightSidePanel/errors/useErrorGroups.ts
@@ -5,6 +5,7 @@ import type { IFuseOptions } from 'fuse.js'
 
 import { useMissingModelStore } from '@/platform/missingModel/missingModelStore'
 import { useExecutionErrorStore } from '@/stores/executionErrorStore'
+import { useMissingNodesErrorStore } from '@/platform/nodeReplacement/missingNodesErrorStore'
 import { useComfyRegistryStore } from '@/stores/comfyRegistryStore'
 import { useCanvasStore } from '@/renderer/core/canvas/canvasStore'
 import { app } from '@/scripts/app'
@@ -195,12 +196,8 @@ function searchErrorGroups(groups: ErrorGroup[], query: string) {
         cardIndex: ci,
         searchableNodeId: card.nodeId ?? '',
         searchableNodeTitle: card.nodeTitle ?? '',
-        searchableMessage: card.errors
-          .map((e: ErrorItem) => e.message)
-          .join(' '),
-        searchableDetails: card.errors
-          .map((e: ErrorItem) => e.details ?? '')
-          .join(' ')
+        searchableMessage: card.errors.map((e) => e.message).join(' '),
+        searchableDetails: card.errors.map((e) => e.details ?? '').join(' ')
       })
     }
   }
@@ -240,6 +237,7 @@ export function useErrorGroups(
   t: (key: string) => string
 ) {
   const executionErrorStore = useExecutionErrorStore()
+  const missingNodesStore = useMissingNodesErrorStore()
   const missingModelStore = useMissingModelStore()
   const canvasStore = useCanvasStore()
   const { inferPackFromNodeName } = useComfyRegistryStore()
@@ -285,7 +283,7 @@ export function useErrorGroups(
 
   const missingNodeCache = computed(() => {
     const map = new Map<string, LGraphNode>()
-    const nodeTypes = executionErrorStore.missingNodesError?.nodeTypes ?? []
+    const nodeTypes = missingNodesStore.missingNodesError?.nodeTypes ?? []
     for (const nodeType of nodeTypes) {
       if (typeof nodeType === 'string') continue
       if (nodeType.nodeId == null) continue
@@ -407,7 +405,7 @@ export function useErrorGroups(
   const asyncResolvedIds = ref<Map<string, string | null>>(new Map())
 
   const pendingTypes = computed(() =>
-    (executionErrorStore.missingNodesError?.nodeTypes ?? []).filter(
+    (missingNodesStore.missingNodesError?.nodeTypes ?? []).filter(
       (n): n is Exclude<MissingNodeType, string> =>
         typeof n !== 'string' && !n.cnrId
     )
@@ -448,6 +446,8 @@ export function useErrorGroups(
       for (const r of results) {
         if (r.status === 'fulfilled') {
           final.set(r.value.type, r.value.packId)
+        } else {
+          console.warn('Failed to resolve pack ID:', r.reason)
         }
       }
       // Clear any remaining RESOLVING markers for failed lookups
@@ -459,8 +459,18 @@ export function useErrorGroups(
     { immediate: true }
   )
 
+  // Evict stale entries when missing nodes are cleared
+  watch(
+    () => missingNodesStore.missingNodesError,
+    (error) => {
+      if (!error && asyncResolvedIds.value.size > 0) {
+        asyncResolvedIds.value = new Map()
+      }
+    }
+  )
+
   const missingPackGroups = computed<MissingPackGroup[]>(() => {
-    const nodeTypes = executionErrorStore.missingNodesError?.nodeTypes ?? []
+    const nodeTypes = missingNodesStore.missingNodesError?.nodeTypes ?? []
     const map = new Map<
       string | null,
       { nodeTypes: MissingNodeType[]; isResolving: boolean }
@@ -522,7 +532,7 @@ export function useErrorGroups(
   })
 
   const swapNodeGroups = computed<SwapNodeGroup[]>(() => {
-    const nodeTypes = executionErrorStore.missingNodesError?.nodeTypes ?? []
+    const nodeTypes = missingNodesStore.missingNodesError?.nodeTypes ?? []
     const map = new Map<string, SwapNodeGroup>()
 
     for (const nodeType of nodeTypes) {
@@ -546,7 +556,7 @@ export function useErrorGroups(
 
   /** Builds an ErrorGroup from missingNodesError. Returns [] when none present. */
   function buildMissingNodeGroups(): ErrorGroup[] {
-    const error = executionErrorStore.missingNodesError
+    const error = missingNodesStore.missingNodesError
     if (!error) return []
 
     const groups: ErrorGroup[] = []
diff --git a/src/components/rightSidePanel/errors/useErrorReport.ts b/src/components/rightSidePanel/errors/useErrorReport.ts
index fc007583450..95340641b9d 100644
--- a/src/components/rightSidePanel/errors/useErrorReport.ts
+++ b/src/components/rightSidePanel/errors/useErrorReport.ts
@@ -2,6 +2,8 @@ import { computed, onMounted, onUnmounted, reactive, toValue } from 'vue'
 
 import type { MaybeRefOrGetter } from 'vue'
 
+import { until } from '@vueuse/core'
+
 import { api } from '@/scripts/api'
 import { app } from '@/scripts/app'
 import { useSystemStatsStore } from '@/stores/systemStatsStore'
@@ -40,24 +42,33 @@ export function useErrorReport(cardSource: MaybeRefOrGetter<ErrorCardData>) {
     if (runtimeErrors.length === 0) return
 
     if (!systemStatsStore.systemStats) {
-      try {
-        await systemStatsStore.refetchSystemStats()
-      } catch {
-        return
+      if (systemStatsStore.isLoading) {
+        await until(systemStatsStore.isLoading).toBe(false)
+      } else {
+        try {
+          await systemStatsStore.refetchSystemStats()
+        } catch (e) {
+          console.warn('Failed to fetch system stats for error report:', e)
+          return
+        }
       }
     }
-    if (cancelled || !systemStatsStore.systemStats) return
-
-    let logs: string
-    try {
-      logs = await api.getLogs()
-    } catch {
-      logs = 'Failed to retrieve server logs'
-    }
+    if (!systemStatsStore.systemStats || cancelled) return
 
+    const logs = await api
+      .getLogs()
+      .catch(() => 'Failed to retrieve server logs')
     if (cancelled) return
 
-    const workflow = app.rootGraph.serialize()
+    const workflow = (() => {
+      try {
+        return app.rootGraph.serialize()
+      } catch (e) {
+        console.warn('Failed to serialize workflow for error report:', e)
+        return null
+      }
+    })()
+    if (!workflow) return
 
     for (const { error, idx } of runtimeErrors) {
       try {
@@ -72,8 +83,8 @@ export function useErrorReport(cardSource: MaybeRefOrGetter<ErrorCardData>) {
           workflow
         })
         enrichedDetails[idx] = report
-      } catch {
-        // Fallback: keep original error.details
+      } catch (e) {
+        console.warn('Failed to generate error report:', e)
       }
     }
   })
diff --git a/src/composables/graph/useErrorClearingHooks.test.ts b/src/composables/graph/useErrorClearingHooks.test.ts
index 3fe38977c65..ea82714a84e 100644
--- a/src/composables/graph/useErrorClearingHooks.test.ts
+++ b/src/composables/graph/useErrorClearingHooks.test.ts
@@ -315,6 +315,45 @@ describe('installErrorClearingHooks lifecycle', () => {
     cleanup()
     expect(graph.onNodeAdded).toBe(originalHook)
   })
+
+  it('restores original node callbacks when a node is removed', () => {
+    const graph = new LGraph()
+    const node = new LGraphNode('test')
+    node.addInput('clip', 'CLIP')
+    node.addWidget('number', 'steps', 20, () => undefined, {})
+    const originalOnConnectionsChange = vi.fn()
+    const originalOnWidgetChanged = vi.fn()
+    node.onConnectionsChange = originalOnConnectionsChange
+    node.onWidgetChanged = originalOnWidgetChanged
+    graph.add(node)
+
+    installErrorClearingHooks(graph)
+
+    // Callbacks should be chained (not the originals)
+    expect(node.onConnectionsChange).not.toBe(originalOnConnectionsChange)
+    expect(node.onWidgetChanged).not.toBe(originalOnWidgetChanged)
+
+    // Simulate node removal via the graph hook
+    graph.onNodeRemoved!(node)
+
+    // Original callbacks should be restored
+    expect(node.onConnectionsChange).toBe(originalOnConnectionsChange)
+    expect(node.onWidgetChanged).toBe(originalOnWidgetChanged)
+  })
+
+  it('does not double-wrap callbacks when installErrorClearingHooks is called twice', () => {
+    const graph = new LGraph()
+    const node = new LGraphNode('test')
+    node.addInput('clip', 'CLIP')
+    graph.add(node)
+
+    installErrorClearingHooks(graph)
+    const chainedAfterFirst = node.onConnectionsChange
+
+    // Install again on the same graph — should be a no-op for existing nodes
+    installErrorClearingHooks(graph)
+    expect(node.onConnectionsChange).toBe(chainedAfterFirst)
+  })
 })
 
 describe('clearWidgetRelatedErrors parameter routing', () => {
diff --git a/src/composables/graph/useErrorClearingHooks.ts b/src/composables/graph/useErrorClearingHooks.ts
index 27fcc0922d5..9f9be0b6429 100644
--- a/src/composables/graph/useErrorClearingHooks.ts
+++ b/src/composables/graph/useErrorClearingHooks.ts
@@ -35,10 +35,22 @@ function resolvePromotedExecId(
 
 const hookedNodes = new WeakSet<LGraphNode>()
 
+type OriginalCallbacks = {
+  onConnectionsChange: LGraphNode['onConnectionsChange']
+  onWidgetChanged: LGraphNode['onWidgetChanged']
+}
+
+const originalCallbacks = new WeakMap<LGraphNode, OriginalCallbacks>()
+
 function installNodeHooks(node: LGraphNode): void {
   if (hookedNodes.has(node)) return
   hookedNodes.add(node)
 
+  originalCallbacks.set(node, {
+    onConnectionsChange: node.onConnectionsChange,
+    onWidgetChanged: node.onWidgetChanged
+  })
+
   node.onConnectionsChange = useChainCallback(
     node.onConnectionsChange,
     function (type, slotIndex, isConnected) {
@@ -82,6 +94,15 @@ function installNodeHooks(node: LGraphNode): void {
   )
 }
 
+function restoreNodeHooks(node: LGraphNode): void {
+  const originals = originalCallbacks.get(node)
+  if (!originals) return
+  node.onConnectionsChange = originals.onConnectionsChange
+  node.onWidgetChanged = originals.onWidgetChanged
+  originalCallbacks.delete(node)
+  hookedNodes.delete(node)
+}
+
 function installNodeHooksRecursive(node: LGraphNode): void {
   installNodeHooks(node)
   if (node.isSubgraphNode?.()) {
@@ -91,6 +112,15 @@ function installNodeHooksRecursive(node: LGraphNode): void {
   }
 }
 
+function restoreNodeHooksRecursive(node: LGraphNode): void {
+  restoreNodeHooks(node)
+  if (node.isSubgraphNode?.()) {
+    for (const innerNode of node.subgraph._nodes ?? []) {
+      restoreNodeHooksRecursive(innerNode)
+    }
+  }
+}
+
 export function installErrorClearingHooks(graph: LGraph): () => void {
   for (const node of graph._nodes ?? []) {
     installNodeHooksRecursive(node)
@@ -102,7 +132,17 @@ export function installErrorClearingHooks(graph: LGraph): () => void {
     originalOnNodeAdded?.call(this, node)
   }
 
+  const originalOnNodeRemoved = graph.onNodeRemoved
+  graph.onNodeRemoved = function (node: LGraphNode) {
+    restoreNodeHooksRecursive(node)
+    originalOnNodeRemoved?.call(this, node)
+  }
+
   return () => {
+    for (const node of graph._nodes ?? []) {
+      restoreNodeHooksRecursive(node)
+    }
     graph.onNodeAdded = originalOnNodeAdded || undefined
+    graph.onNodeRemoved = originalOnNodeRemoved || undefined
   }
 }
diff --git a/src/composables/graph/useNodeErrorFlagSync.ts b/src/composables/graph/useNodeErrorFlagSync.ts
new file mode 100644
index 00000000000..bb32b823633
--- /dev/null
+++ b/src/composables/graph/useNodeErrorFlagSync.ts
@@ -0,0 +1,111 @@
+import type { Ref } from 'vue'
+import { computed, watch } from 'vue'
+
+import type { LGraph, LGraphNode } from '@/lib/litegraph/src/litegraph'
+import type { useMissingModelStore } from '@/platform/missingModel/missingModelStore'
+import { useSettingStore } from '@/platform/settings/settingStore'
+import { app } from '@/scripts/app'
+import type { NodeError } from '@/schemas/apiSchema'
+import { getParentExecutionIds } from '@/types/nodeIdentification'
+import { forEachNode, getNodeByExecutionId } from '@/utils/graphTraversalUtil'
+
+function setNodeHasErrors(node: LGraphNode, hasErrors: boolean): void {
+  if (node.has_errors === hasErrors) return
+  const oldValue = node.has_errors
+  node.has_errors = hasErrors
+  node.graph?.trigger('node:property:changed', {
+    type: 'node:property:changed',
+    nodeId: node.id,
+    property: 'has_errors',
+    oldValue,
+    newValue: hasErrors
+  })
+}
+
+/**
+ * Single-pass reconciliation of node error flags.
+ * Collects the set of nodes that should have errors, then walks all nodes
+ * once, setting each flag exactly once. This avoids the redundant
+ * true→false→true transition (and duplicate events) that a clear-then-apply
+ * approach would cause.
+ */
+function reconcileNodeErrorFlags(
+  rootGraph: LGraph,
+  nodeErrors: Record<string, NodeError> | null,
+  missingModelExecIds: Set<string>
+): void {
+  // Collect nodes and slot info that should be flagged
+  // Includes both error-owning nodes and their ancestor containers
+  const flaggedNodes = new Set<LGraphNode>()
+  const errorSlots = new Map<LGraphNode, Set<string>>()
+
+  if (nodeErrors) {
+    for (const [executionId, nodeError] of Object.entries(nodeErrors)) {
+      const node = getNodeByExecutionId(rootGraph, executionId)
+      if (!node) continue
+
+      flaggedNodes.add(node)
+      const slotNames = new Set<string>()
+      for (const error of nodeError.errors) {
+        const name = error.extra_info?.input_name
+        if (name) slotNames.add(name)
+      }
+      if (slotNames.size > 0) errorSlots.set(node, slotNames)
+
+      for (const parentId of getParentExecutionIds(executionId)) {
+        const parentNode = getNodeByExecutionId(rootGraph, parentId)
+        if (parentNode) flaggedNodes.add(parentNode)
+      }
+    }
+  }
+
+  for (const execId of missingModelExecIds) {
+    const node = getNodeByExecutionId(rootGraph, execId)
+    if (node) flaggedNodes.add(node)
+  }
+
+  forEachNode(rootGraph, (node) => {
+    setNodeHasErrors(node, flaggedNodes.has(node))
+
+    if (node.inputs) {
+      const nodeSlotNames = errorSlots.get(node)
+      for (const slot of node.inputs) {
+        slot.hasErrors = !!nodeSlotNames?.has(slot.name)
+      }
+    }
+  })
+}
+
+export function useNodeErrorFlagSync(
+  lastNodeErrors: Ref<Record<string, NodeError> | null>,
+  missingModelStore: ReturnType<typeof useMissingModelStore>
+): () => void {
+  const settingStore = useSettingStore()
+  const showErrorsTab = computed(() =>
+    settingStore.get('Comfy.RightSidePanel.ShowErrorsTab')
+  )
+
+  const stop = watch(
+    [
+      lastNodeErrors,
+      () => missingModelStore.missingModelNodeIds,
+      showErrorsTab
+    ],
+    () => {
+      if (!app.isGraphReady) return
+      // Legacy (LGraphNode) only: suppress missing-model error flags when
+      // the Errors tab is hidden, since legacy nodes lack the per-widget
+      // red highlight that Vue nodes use to indicate *why* a node has errors.
+      // Vue nodes compute hasAnyError independently and are unaffected.
+      reconcileNodeErrorFlags(
+        app.rootGraph,
+        lastNodeErrors.value,
+        showErrorsTab.value
+          ? missingModelStore.missingModelAncestorExecutionIds
+          : new Set()
+      )
+    },
+    { flush: 'post' }
+  )
+  return stop
+}
diff --git a/src/workbench/extensions/manager/utils/missingNodeErrorUtil.test.ts b/src/platform/nodeReplacement/cnrIdUtil.test.ts
similarity index 95%
rename from src/workbench/extensions/manager/utils/missingNodeErrorUtil.test.ts
rename to src/platform/nodeReplacement/cnrIdUtil.test.ts
index 242d46c2339..01a29ace68e 100644
--- a/src/workbench/extensions/manager/utils/missingNodeErrorUtil.test.ts
+++ b/src/platform/nodeReplacement/cnrIdUtil.test.ts
@@ -2,10 +2,7 @@ import { describe, expect, it } from 'vitest'
 
 import type { LGraphNode } from '@/lib/litegraph/src/litegraph'
 
-import {
-  getCnrIdFromProperties,
-  getCnrIdFromNode
-} from './missingNodeErrorUtil'
+import { getCnrIdFromNode, getCnrIdFromProperties } from './cnrIdUtil'
 
 describe('getCnrIdFromProperties', () => {
   it('returns cnr_id when present', () => {
diff --git a/src/workbench/extensions/manager/utils/missingNodeErrorUtil.ts b/src/platform/nodeReplacement/cnrIdUtil.ts
similarity index 100%
rename from src/workbench/extensions/manager/utils/missingNodeErrorUtil.ts
rename to src/platform/nodeReplacement/cnrIdUtil.ts
diff --git a/src/platform/nodeReplacement/missingNodeScan.test.ts b/src/platform/nodeReplacement/missingNodeScan.test.ts
index bf3b74cafdf..0652a0a7859 100644
--- a/src/platform/nodeReplacement/missingNodeScan.test.ts
+++ b/src/platform/nodeReplacement/missingNodeScan.test.ts
@@ -20,8 +20,8 @@ vi.mock('@/utils/graphTraversalUtil', () => ({
   getExecutionIdByNode: vi.fn()
 }))
 
-vi.mock('@/workbench/extensions/manager/utils/missingNodeErrorUtil', () => ({
-  getCnrIdFromNode: vi.fn(() => null)
+vi.mock('@/platform/nodeReplacement/cnrIdUtil', () => ({
+  getCnrIdFromNode: vi.fn(() => undefined)
 }))
 
 vi.mock('@/i18n', () => ({
@@ -48,11 +48,10 @@ import {
   collectAllNodes,
   getExecutionIdByNode
 } from '@/utils/graphTraversalUtil'
-// eslint-disable-next-line import-x/no-restricted-paths
-import { getCnrIdFromNode } from '@/workbench/extensions/manager/utils/missingNodeErrorUtil'
+import { getCnrIdFromNode } from '@/platform/nodeReplacement/cnrIdUtil'
 import { useNodeReplacementStore } from '@/platform/nodeReplacement/nodeReplacementStore'
 import { rescanAndSurfaceMissingNodes } from './missingNodeScan'
-import { useExecutionErrorStore } from '@/stores/executionErrorStore'
+import { useMissingNodesErrorStore } from '@/platform/nodeReplacement/missingNodesErrorStore'
 
 function mockNode(
   id: number,
@@ -72,7 +71,7 @@ function mockGraph(): LGraph {
 }
 
 function getMissingNodesError(
-  store: ReturnType<typeof useExecutionErrorStore>
+  store: ReturnType<typeof useMissingNodesErrorStore>
 ) {
   const error = store.missingNodesError
   if (!error) throw new Error('Expected missingNodesError to be defined')
@@ -99,7 +98,7 @@ describe('scanMissingNodes (via rescanAndSurfaceMissingNodes)', () => {
 
     rescanAndSurfaceMissingNodes(mockGraph())
 
-    const store = useExecutionErrorStore()
+    const store = useMissingNodesErrorStore()
     expect(store.missingNodesError).toBeNull()
   })
 
@@ -112,7 +111,7 @@ describe('scanMissingNodes (via rescanAndSurfaceMissingNodes)', () => {
 
     rescanAndSurfaceMissingNodes(mockGraph())
 
-    const store = useExecutionErrorStore()
+    const store = useMissingNodesErrorStore()
     const error = getMissingNodesError(store)
     expect(error.nodeTypes).toHaveLength(2)
   })
@@ -129,7 +128,7 @@ describe('scanMissingNodes (via rescanAndSurfaceMissingNodes)', () => {
 
     rescanAndSurfaceMissingNodes(mockGraph())
 
-    const store = useExecutionErrorStore()
+    const store = useMissingNodesErrorStore()
     const error = getMissingNodesError(store)
     expect(error.nodeTypes).toHaveLength(1)
     const missing = error.nodeTypes[0]
@@ -142,7 +141,7 @@ describe('scanMissingNodes (via rescanAndSurfaceMissingNodes)', () => {
 
     rescanAndSurfaceMissingNodes(mockGraph())
 
-    const store = useExecutionErrorStore()
+    const store = useMissingNodesErrorStore()
     const error = getMissingNodesError(store)
     const missing = error.nodeTypes[0]
     expect(typeof missing !== 'string' && missing.nodeId).toBe('exec-42')
@@ -154,7 +153,7 @@ describe('scanMissingNodes (via rescanAndSurfaceMissingNodes)', () => {
 
     rescanAndSurfaceMissingNodes(mockGraph())
 
-    const store = useExecutionErrorStore()
+    const store = useMissingNodesErrorStore()
     const error = getMissingNodesError(store)
     const missing = error.nodeTypes[0]
     expect(typeof missing !== 'string' && missing.nodeId).toBe('99')
@@ -167,7 +166,7 @@ describe('scanMissingNodes (via rescanAndSurfaceMissingNodes)', () => {
 
     rescanAndSurfaceMissingNodes(mockGraph())
 
-    const store = useExecutionErrorStore()
+    const store = useMissingNodesErrorStore()
     const error = getMissingNodesError(store)
     const missing = error.nodeTypes[0]
     expect(typeof missing !== 'string' && missing.cnrId).toBe(
@@ -194,7 +193,7 @@ describe('scanMissingNodes (via rescanAndSurfaceMissingNodes)', () => {
 
     rescanAndSurfaceMissingNodes(mockGraph())
 
-    const store = useExecutionErrorStore()
+    const store = useMissingNodesErrorStore()
     const error = getMissingNodesError(store)
     const missing = error.nodeTypes[0]
     expect(typeof missing !== 'string' && missing.isReplaceable).toBe(true)
@@ -209,7 +208,7 @@ describe('scanMissingNodes (via rescanAndSurfaceMissingNodes)', () => {
 
     rescanAndSurfaceMissingNodes(mockGraph())
 
-    const store = useExecutionErrorStore()
+    const store = useMissingNodesErrorStore()
     const error = getMissingNodesError(store)
     const missing = error.nodeTypes[0]
     expect(typeof missing !== 'string' && missing.isReplaceable).toBe(false)
@@ -225,7 +224,7 @@ describe('scanMissingNodes (via rescanAndSurfaceMissingNodes)', () => {
 
     rescanAndSurfaceMissingNodes(mockGraph())
 
-    const store = useExecutionErrorStore()
+    const store = useMissingNodesErrorStore()
     const error = getMissingNodesError(store)
     const missing = error.nodeTypes[0]
     expect(typeof missing !== 'string' && missing.type).toBe('OriginalType')
diff --git a/src/platform/nodeReplacement/missingNodeScan.ts b/src/platform/nodeReplacement/missingNodeScan.ts
index c44de073894..002f992acf3 100644
--- a/src/platform/nodeReplacement/missingNodeScan.ts
+++ b/src/platform/nodeReplacement/missingNodeScan.ts
@@ -2,13 +2,13 @@ import { LiteGraph } from '@/lib/litegraph/src/litegraph'
 import type { LGraph } from '@/lib/litegraph/src/litegraph'
 import { useNodeReplacementStore } from '@/platform/nodeReplacement/nodeReplacementStore'
 import { useExecutionErrorStore } from '@/stores/executionErrorStore'
+import { useMissingNodesErrorStore } from '@/platform/nodeReplacement/missingNodesErrorStore'
 import type { MissingNodeType } from '@/types/comfy'
 import {
   collectAllNodes,
   getExecutionIdByNode
 } from '@/utils/graphTraversalUtil'
-// eslint-disable-next-line import-x/no-restricted-paths
-import { getCnrIdFromNode } from '@/workbench/extensions/manager/utils/missingNodeErrorUtil'
+import { getCnrIdFromNode } from '@/platform/nodeReplacement/cnrIdUtil'
 
 /** Scan the live graph for unregistered node types and build a full MissingNodeType list. */
 function scanMissingNodes(rootGraph: LGraph): MissingNodeType[] {
@@ -41,5 +41,7 @@ function scanMissingNodes(rootGraph: LGraph): MissingNodeType[] {
 /** Re-scan the graph for missing nodes and update the error store. */
 export function rescanAndSurfaceMissingNodes(rootGraph: LGraph): void {
   const types = scanMissingNodes(rootGraph)
-  useExecutionErrorStore().surfaceMissingNodes(types)
+  if (useMissingNodesErrorStore().surfaceMissingNodes(types)) {
+    useExecutionErrorStore().showErrorOverlay()
+  }
 }
diff --git a/src/platform/nodeReplacement/missingNodesErrorStore.test.ts b/src/platform/nodeReplacement/missingNodesErrorStore.test.ts
new file mode 100644
index 00000000000..6d051f3527a
--- /dev/null
+++ b/src/platform/nodeReplacement/missingNodesErrorStore.test.ts
@@ -0,0 +1,215 @@
+import { createPinia, setActivePinia } from 'pinia'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+import type { MissingNodeType } from '@/types/comfy'
+
+vi.mock('@/i18n', () => ({
+  st: vi.fn((_key: string, fallback: string) => fallback)
+}))
+
+vi.mock('@/platform/distribution/types', () => ({
+  isCloud: false
+}))
+
+const mockShowErrorsTab = vi.hoisted(() => ({ value: false }))
+
+vi.mock('@/platform/settings/settingStore', () => ({
+  useSettingStore: vi.fn(() => ({
+    get: vi.fn(() => mockShowErrorsTab.value)
+  }))
+}))
+
+import { useMissingNodesErrorStore } from './missingNodesErrorStore'
+
+describe('missingNodesErrorStore', () => {
+  beforeEach(() => {
+    setActivePinia(createPinia())
+  })
+
+  describe('setMissingNodeTypes', () => {
+    it('sets missingNodesError with provided types', () => {
+      const store = useMissingNodesErrorStore()
+      const types: MissingNodeType[] = [
+        { type: 'NodeA', nodeId: '1', isReplaceable: false }
+      ]
+      store.setMissingNodeTypes(types)
+
+      expect(store.missingNodesError).not.toBeNull()
+      expect(store.missingNodesError?.nodeTypes).toHaveLength(1)
+      expect(store.hasMissingNodes).toBe(true)
+    })
+
+    it('clears missingNodesError when given empty array', () => {
+      const store = useMissingNodesErrorStore()
+      store.setMissingNodeTypes([
+        { type: 'NodeA', nodeId: '1', isReplaceable: false }
+      ])
+      expect(store.missingNodesError).not.toBeNull()
+
+      store.setMissingNodeTypes([])
+      expect(store.missingNodesError).toBeNull()
+      expect(store.hasMissingNodes).toBe(false)
+    })
+
+    it('deduplicates string entries by value', () => {
+      const store = useMissingNodesErrorStore()
+      store.setMissingNodeTypes([
+        'NodeA',
+        'NodeA',
+        'NodeB'
+      ] as MissingNodeType[])
+
+      expect(store.missingNodesError?.nodeTypes).toHaveLength(2)
+    })
+
+    it('deduplicates object entries by nodeId when present', () => {
+      const store = useMissingNodesErrorStore()
+      store.setMissingNodeTypes([
+        { type: 'NodeA', nodeId: '1', isReplaceable: false },
+        { type: 'NodeA', nodeId: '1', isReplaceable: false },
+        { type: 'NodeA', nodeId: '2', isReplaceable: false }
+      ])
+
+      expect(store.missingNodesError?.nodeTypes).toHaveLength(2)
+    })
+
+    it('deduplicates object entries by type when nodeId is absent', () => {
+      const store = useMissingNodesErrorStore()
+      store.setMissingNodeTypes([
+        { type: 'NodeA', isReplaceable: false },
+        { type: 'NodeA', isReplaceable: true }
+      ] as MissingNodeType[])
+
+      expect(store.missingNodesError?.nodeTypes).toHaveLength(1)
+    })
+
+    it('keeps distinct nodeIds even when type is the same', () => {
+      const store = useMissingNodesErrorStore()
+      store.setMissingNodeTypes([
+        { type: 'NodeA', nodeId: '1', isReplaceable: false },
+        { type: 'NodeA', nodeId: '2', isReplaceable: false },
+        { type: 'NodeA', nodeId: '3', isReplaceable: false }
+      ])
+
+      expect(store.missingNodesError?.nodeTypes).toHaveLength(3)
+    })
+  })
+
+  describe('surfaceMissingNodes', () => {
+    beforeEach(() => {
+      mockShowErrorsTab.value = false
+    })
+
+    it('stores missing node types and returns false when setting disabled', () => {
+      const store = useMissingNodesErrorStore()
+      const types: MissingNodeType[] = [
+        { type: 'NodeA', nodeId: '1', isReplaceable: false }
+      ]
+      const shouldShowOverlay = store.surfaceMissingNodes(types)
+
+      expect(store.missingNodesError).not.toBeNull()
+      expect(store.missingNodesError?.nodeTypes).toHaveLength(1)
+      expect(store.hasMissingNodes).toBe(true)
+      expect(shouldShowOverlay).toBe(false)
+    })
+
+    it('returns true when ShowErrorsTab setting is enabled', () => {
+      mockShowErrorsTab.value = true
+      const store = useMissingNodesErrorStore()
+      const shouldShowOverlay = store.surfaceMissingNodes([
+        { type: 'NodeA', nodeId: '1', isReplaceable: false }
+      ])
+
+      expect(shouldShowOverlay).toBe(true)
+    })
+
+    it('returns false when ShowErrorsTab setting is disabled', () => {
+      mockShowErrorsTab.value = false
+      const store = useMissingNodesErrorStore()
+      const shouldShowOverlay = store.surfaceMissingNodes([
+        { type: 'NodeA', nodeId: '1', isReplaceable: false }
+      ])
+
+      expect(shouldShowOverlay).toBe(false)
+    })
+
+    it('returns false for empty types even when setting is enabled', () => {
+      mockShowErrorsTab.value = true
+      const store = useMissingNodesErrorStore()
+      const shouldShowOverlay = store.surfaceMissingNodes([])
+
+      expect(shouldShowOverlay).toBe(false)
+    })
+
+    it('deduplicates node types', () => {
+      const store = useMissingNodesErrorStore()
+      store.surfaceMissingNodes([
+        { type: 'NodeA', nodeId: '1', isReplaceable: false },
+        { type: 'NodeA', nodeId: '1', isReplaceable: false },
+        { type: 'NodeB', nodeId: '2', isReplaceable: false }
+      ])
+
+      expect(store.missingNodesError?.nodeTypes).toHaveLength(2)
+    })
+  })
+
+  describe('removeMissingNodesByType', () => {
+    it('removes matching types from the missing nodes list', () => {
+      const store = useMissingNodesErrorStore()
+      store.setMissingNodeTypes([
+        { type: 'NodeA', nodeId: '1', isReplaceable: false },
+        { type: 'NodeB', nodeId: '2', isReplaceable: false },
+        { type: 'NodeC', nodeId: '3', isReplaceable: false }
+      ])
+
+      store.removeMissingNodesByType(['NodeA', 'NodeC'])
+
+      expect(store.missingNodesError?.nodeTypes).toHaveLength(1)
+      const remaining = store.missingNodesError?.nodeTypes[0]
+      expect(typeof remaining !== 'string' && remaining?.type).toBe('NodeB')
+    })
+
+    it('clears missingNodesError when all types are removed', () => {
+      const store = useMissingNodesErrorStore()
+      store.setMissingNodeTypes([
+        { type: 'NodeA', nodeId: '1', isReplaceable: false }
+      ])
+
+      store.removeMissingNodesByType(['NodeA'])
+
+      expect(store.missingNodesError).toBeNull()
+      expect(store.hasMissingNodes).toBe(false)
+    })
+
+    it('does nothing when missingNodesError is null', () => {
+      const store = useMissingNodesErrorStore()
+      expect(store.missingNodesError).toBeNull()
+
+      store.removeMissingNodesByType(['NodeA'])
+      expect(store.missingNodesError).toBeNull()
+    })
+
+    it('does nothing when removing non-existent types', () => {
+      const store = useMissingNodesErrorStore()
+      store.setMissingNodeTypes([
+        { type: 'NodeA', nodeId: '1', isReplaceable: false }
+      ])
+
+      store.removeMissingNodesByType(['NonExistent'])
+
+      expect(store.missingNodesError?.nodeTypes).toHaveLength(1)
+    })
+
+    it('handles removing from string entries', () => {
+      const store = useMissingNodesErrorStore()
+      store.setMissingNodeTypes([
+        'StringNodeA',
+        'StringNodeB'
+      ] as MissingNodeType[])
+
+      store.removeMissingNodesByType(['StringNodeA'])
+
+      expect(store.missingNodesError?.nodeTypes).toHaveLength(1)
+    })
+  })
+})
diff --git a/src/platform/nodeReplacement/missingNodesErrorStore.ts b/src/platform/nodeReplacement/missingNodesErrorStore.ts
new file mode 100644
index 00000000000..a71c98d112f
--- /dev/null
+++ b/src/platform/nodeReplacement/missingNodesErrorStore.ts
@@ -0,0 +1,125 @@
+import { defineStore } from 'pinia'
+import { computed, ref } from 'vue'
+
+import { st } from '@/i18n'
+import type { LGraphNode } from '@/lib/litegraph/src/litegraph'
+import { isCloud } from '@/platform/distribution/types'
+import { useSettingStore } from '@/platform/settings/settingStore'
+import { app } from '@/scripts/app'
+import type { MissingNodeType } from '@/types/comfy'
+import { getAncestorExecutionIds } from '@/types/nodeIdentification'
+import type { NodeExecutionId } from '@/types/nodeIdentification'
+import { getExecutionIdByNode } from '@/utils/graphTraversalUtil'
+
+interface MissingNodesError {
+  message: string
+  nodeTypes: MissingNodeType[]
+}
+
+export const useMissingNodesErrorStore = defineStore(
+  'missingNodesError',
+  () => {
+    const missingNodesError = ref<MissingNodesError | null>(null)
+
+    function setMissingNodeTypes(types: MissingNodeType[]) {
+      if (!types.length) {
+        missingNodesError.value = null
+        return
+      }
+      const seen = new Set<string>()
+      const uniqueTypes = types.filter((node) => {
+        // For string entries (group nodes), deduplicate by the string itself.
+        // For object entries, prefer nodeId so multiple instances of the same
+        // type are kept as separate rows; fall back to type if nodeId is absent.
+        const isString = typeof node === 'string'
+        let key: string
+        if (isString) {
+          key = node
+        } else if (node.nodeId != null) {
+          key = String(node.nodeId)
+        } else {
+          key = node.type
+        }
+        if (seen.has(key)) return false
+        seen.add(key)
+        return true
+      })
+      missingNodesError.value = {
+        message: isCloud
+          ? st(
+              'rightSidePanel.missingNodePacks.unsupportedTitle',
+              'Unsupported Node Packs'
+            )
+          : st('rightSidePanel.missingNodePacks.title', 'Missing Node Packs'),
+        nodeTypes: uniqueTypes
+      }
+    }
+
+    /** Set missing node types. Returns true if the Errors tab is enabled and types were set. */
+    function surfaceMissingNodes(types: MissingNodeType[]): boolean {
+      setMissingNodeTypes(types)
+      return (
+        types.length > 0 &&
+        useSettingStore().get('Comfy.RightSidePanel.ShowErrorsTab')
+      )
+    }
+
+    /** Remove specific node types from the missing nodes list (e.g. after replacement). */
+    function removeMissingNodesByType(typesToRemove: string[]) {
+      if (!missingNodesError.value) return
+      const removeSet = new Set(typesToRemove)
+      const remaining = missingNodesError.value.nodeTypes.filter((node) => {
+        const nodeType = typeof node === 'string' ? node : node.type
+        return !removeSet.has(nodeType)
+      })
+      setMissingNodeTypes(remaining)
+    }
+
+    const hasMissingNodes = computed(() => !!missingNodesError.value)
+
+    const missingNodeCount = computed(
+      () => missingNodesError.value?.nodeTypes.length ?? 0
+    )
+
+    /**
+     * Set of all execution ID prefixes derived from missing node execution IDs,
+     * including the missing nodes themselves.
+     *
+     * Example: missing node at "65:70:63" → Set { "65", "65:70", "65:70:63" }
+     */
+    const missingAncestorExecutionIds = computed<Set<NodeExecutionId>>(() => {
+      const ids = new Set<NodeExecutionId>()
+      const error = missingNodesError.value
+      if (!error) return ids
+
+      for (const nodeType of error.nodeTypes) {
+        if (typeof nodeType === 'string') continue
+        if (nodeType.nodeId == null) continue
+        for (const id of getAncestorExecutionIds(String(nodeType.nodeId))) {
+          ids.add(id)
+        }
+      }
+
+      return ids
+    })
+
+    /** True if the node has a missing node inside it at any nesting depth. */
+    function isContainerWithMissingNode(node: LGraphNode): boolean {
+      if (!app.isGraphReady) return false
+      const execId = getExecutionIdByNode(app.rootGraph, node)
+      if (!execId) return false
+      return missingAncestorExecutionIds.value.has(execId)
+    }
+
+    return {
+      missingNodesError,
+      setMissingNodeTypes,
+      surfaceMissingNodes,
+      removeMissingNodesByType,
+      hasMissingNodes,
+      missingNodeCount,
+      missingAncestorExecutionIds,
+      isContainerWithMissingNode
+    }
+  }
+)
diff --git a/src/platform/nodeReplacement/useNodeReplacement.test.ts b/src/platform/nodeReplacement/useNodeReplacement.test.ts
index 7f3af48110c..f3a60f27782 100644
--- a/src/platform/nodeReplacement/useNodeReplacement.test.ts
+++ b/src/platform/nodeReplacement/useNodeReplacement.test.ts
@@ -47,8 +47,8 @@ vi.mock('@/i18n', () => ({
 const { mockRemoveMissingNodesByType } = vi.hoisted(() => ({
   mockRemoveMissingNodesByType: vi.fn()
 }))
-vi.mock('@/stores/executionErrorStore', () => ({
-  useExecutionErrorStore: vi.fn(() => ({
+vi.mock('@/platform/nodeReplacement/missingNodesErrorStore', () => ({
+  useMissingNodesErrorStore: vi.fn(() => ({
     removeMissingNodesByType: mockRemoveMissingNodesByType
   }))
 }))
diff --git a/src/platform/nodeReplacement/useNodeReplacement.ts b/src/platform/nodeReplacement/useNodeReplacement.ts
index 57d01e69fdf..c272cfe3070 100644
--- a/src/platform/nodeReplacement/useNodeReplacement.ts
+++ b/src/platform/nodeReplacement/useNodeReplacement.ts
@@ -7,7 +7,7 @@ import type { NodeReplacement } from '@/platform/nodeReplacement/types'
 import { useToastStore } from '@/platform/updates/common/toastStore'
 import { useWorkflowStore } from '@/platform/workflow/management/stores/workflowStore'
 import { app, sanitizeNodeName } from '@/scripts/app'
-import { useExecutionErrorStore } from '@/stores/executionErrorStore'
+import { useMissingNodesErrorStore } from '@/platform/nodeReplacement/missingNodesErrorStore'
 import type { MissingNodeType } from '@/types/comfy'
 import { collectAllNodes } from '@/utils/graphTraversalUtil'
 
@@ -329,24 +329,24 @@ export function useNodeReplacement() {
 
   /**
    * Replaces all nodes in a single swap group and removes successfully
-   * replaced types from the execution error store.
+   * replaced types from the missing nodes error store.
    */
   function replaceGroup(group: ReplacementGroup): void {
     const replaced = replaceNodesInPlace(group.nodeTypes)
     if (replaced.length > 0) {
-      useExecutionErrorStore().removeMissingNodesByType(replaced)
+      useMissingNodesErrorStore().removeMissingNodesByType(replaced)
     }
   }
 
   /**
    * Replaces every available node across all swap groups and removes
-   * the succeeded types from the execution error store.
+   * the succeeded types from the missing nodes error store.
    */
   function replaceAllGroups(groups: ReplacementGroup[]): void {
     const allNodeTypes = groups.flatMap((g) => g.nodeTypes)
     const replaced = replaceNodesInPlace(allNodeTypes)
     if (replaced.length > 0) {
-      useExecutionErrorStore().removeMissingNodesByType(replaced)
+      useMissingNodesErrorStore().removeMissingNodesByType(replaced)
     }
   }
 
diff --git a/src/platform/workflow/core/services/workflowService.test.ts b/src/platform/workflow/core/services/workflowService.test.ts
index e44fbe6765e..7e0f2f5131b 100644
--- a/src/platform/workflow/core/services/workflowService.test.ts
+++ b/src/platform/workflow/core/services/workflowService.test.ts
@@ -12,7 +12,7 @@ import { useToastStore } from '@/platform/updates/common/toastStore'
 import type { ComfyWorkflow } from '@/platform/workflow/management/stores/workflowStore'
 import { useWorkflowStore } from '@/platform/workflow/management/stores/workflowStore'
 import { useWorkflowService } from '@/platform/workflow/core/services/workflowService'
-import { useExecutionErrorStore } from '@/stores/executionErrorStore'
+import { useMissingNodesErrorStore } from '@/platform/nodeReplacement/missingNodesErrorStore'
 import { app } from '@/scripts/app'
 import { useAppMode } from '@/composables/useAppMode'
 import type { AppMode } from '@/composables/useAppMode'
@@ -160,7 +160,7 @@ describe('useWorkflowService', () => {
       useWorkflowService().showPendingWarnings(workflow)
 
       expect(
-        useExecutionErrorStore().surfaceMissingNodes
+        useMissingNodesErrorStore().surfaceMissingNodes
       ).not.toHaveBeenCalled()
     })
 
@@ -170,9 +170,9 @@ describe('useWorkflowService', () => {
 
       useWorkflowService().showPendingWarnings(workflow)
 
-      expect(useExecutionErrorStore().surfaceMissingNodes).toHaveBeenCalledWith(
-        missingNodeTypes
-      )
+      expect(
+        useMissingNodesErrorStore().surfaceMissingNodes
+      ).toHaveBeenCalledWith(missingNodeTypes)
       expect(workflow.pendingWarnings).toBeNull()
     })
 
@@ -185,9 +185,9 @@ describe('useWorkflowService', () => {
 
       useWorkflowService().showPendingWarnings(workflow)
 
-      expect(useExecutionErrorStore().surfaceMissingNodes).toHaveBeenCalledWith(
-        ['CustomNode1']
-      )
+      expect(
+        useMissingNodesErrorStore().surfaceMissingNodes
+      ).toHaveBeenCalledWith(['CustomNode1'])
       expect(workflow.pendingWarnings).toBeNull()
     })
 
@@ -201,7 +201,7 @@ describe('useWorkflowService', () => {
       service.showPendingWarnings(workflow)
 
       expect(
-        useExecutionErrorStore().surfaceMissingNodes
+        useMissingNodesErrorStore().surfaceMissingNodes
       ).toHaveBeenCalledTimes(1)
     })
   })
@@ -226,7 +226,7 @@ describe('useWorkflowService', () => {
       )
 
       expect(
-        useExecutionErrorStore().surfaceMissingNodes
+        useMissingNodesErrorStore().surfaceMissingNodes
       ).not.toHaveBeenCalled()
 
       await useWorkflowService().openWorkflow(workflow)
@@ -238,9 +238,9 @@ describe('useWorkflowService', () => {
         workflow,
         expect.objectContaining({ deferWarnings: true })
       )
-      expect(useExecutionErrorStore().surfaceMissingNodes).toHaveBeenCalledWith(
-        ['CustomNode1']
-      )
+      expect(
+        useMissingNodesErrorStore().surfaceMissingNodes
+      ).toHaveBeenCalledWith(['CustomNode1'])
       expect(workflow.pendingWarnings).toBeNull()
     })
 
@@ -258,20 +258,20 @@ describe('useWorkflowService', () => {
 
       await service.openWorkflow(workflow1)
       expect(
-        useExecutionErrorStore().surfaceMissingNodes
+        useMissingNodesErrorStore().surfaceMissingNodes
       ).toHaveBeenCalledTimes(1)
-      expect(useExecutionErrorStore().surfaceMissingNodes).toHaveBeenCalledWith(
-        ['MissingNodeA']
-      )
+      expect(
+        useMissingNodesErrorStore().surfaceMissingNodes
+      ).toHaveBeenCalledWith(['MissingNodeA'])
       expect(workflow1.pendingWarnings).toBeNull()
       expect(workflow2.pendingWarnings).not.toBeNull()
 
       await service.openWorkflow(workflow2)
       expect(
-        useExecutionErrorStore().surfaceMissingNodes
+        useMissingNodesErrorStore().surfaceMissingNodes
       ).toHaveBeenCalledTimes(2)
       expect(
-        useExecutionErrorStore().surfaceMissingNodes
+        useMissingNodesErrorStore().surfaceMissingNodes
       ).toHaveBeenLastCalledWith(['MissingNodeB'])
       expect(workflow2.pendingWarnings).toBeNull()
     })
@@ -286,12 +286,12 @@ describe('useWorkflowService', () => {
 
       await service.openWorkflow(workflow, { force: true })
       expect(
-        useExecutionErrorStore().surfaceMissingNodes
+        useMissingNodesErrorStore().surfaceMissingNodes
       ).toHaveBeenCalledTimes(1)
 
       await service.openWorkflow(workflow, { force: true })
       expect(
-        useExecutionErrorStore().surfaceMissingNodes
+        useMissingNodesErrorStore().surfaceMissingNodes
       ).toHaveBeenCalledTimes(1)
     })
   })
diff --git a/src/platform/workflow/core/services/workflowService.ts b/src/platform/workflow/core/services/workflowService.ts
index 51444fbe23c..5bf1df4feb7 100644
--- a/src/platform/workflow/core/services/workflowService.ts
+++ b/src/platform/workflow/core/services/workflowService.ts
@@ -23,6 +23,7 @@ import type { AppMode } from '@/composables/useAppMode'
 import { useDomWidgetStore } from '@/stores/domWidgetStore'
 import { useAppModeStore } from '@/stores/appModeStore'
 import { useExecutionErrorStore } from '@/stores/executionErrorStore'
+import { useMissingNodesErrorStore } from '@/platform/nodeReplacement/missingNodesErrorStore'
 import { useWorkspaceStore } from '@/stores/workspaceStore'
 import {
   appendJsonExt,
@@ -43,6 +44,7 @@ export const useWorkflowService = () => {
   const workflowThumbnail = useWorkflowThumbnail()
   const domWidgetStore = useDomWidgetStore()
   const executionErrorStore = useExecutionErrorStore()
+  const missingNodesErrorStore = useMissingNodesErrorStore()
   const workflowDraftStore = useWorkflowDraftStore()
 
   function confirmOverwrite(targetPath: string) {
@@ -542,7 +544,9 @@ export const useWorkflowService = () => {
     wf.pendingWarnings = null
 
     if (missingNodeTypes?.length) {
-      executionErrorStore.surfaceMissingNodes(missingNodeTypes)
+      if (missingNodesErrorStore.surfaceMissingNodes(missingNodeTypes)) {
+        executionErrorStore.showErrorOverlay()
+      }
     }
   }
 
diff --git a/src/renderer/extensions/vueNodes/VideoPreview.vue b/src/renderer/extensions/vueNodes/VideoPreview.vue
index 045f296f1e8..e4ef90e4f0f 100644
--- a/src/renderer/extensions/vueNodes/VideoPreview.vue
+++ b/src/renderer/extensions/vueNodes/VideoPreview.vue
@@ -101,7 +101,11 @@
 
     <!-- Video Dimensions -->
     <div class="mt-2 text-center text-xs text-muted-foreground">
-      <span v-if="videoError" class="text-red-400">
+      <span
+        v-if="videoError"
+        class="text-red-400"
+        data-testid="error-loading-video"
+      >
         {{ $t('g.errorLoadingVideo') }}
       </span>
       <span v-else-if="showLoader" class="text-smoke-400">
diff --git a/src/renderer/extensions/vueNodes/components/ImagePreview.vue b/src/renderer/extensions/vueNodes/components/ImagePreview.vue
index e51691eb82c..1071ee0bb59 100644
--- a/src/renderer/extensions/vueNodes/components/ImagePreview.vue
+++ b/src/renderer/extensions/vueNodes/components/ImagePreview.vue
@@ -117,7 +117,11 @@
       v-if="viewMode === 'gallery'"
       class="pt-2 text-center text-xs text-base-foreground"
     >
-      <span v-if="imageError" class="text-error">
+      <span
+        v-if="imageError"
+        class="text-error"
+        data-testid="error-loading-image"
+      >
         {{ $t('g.errorLoadingImage') }}
       </span>
       <span v-else-if="showLoader" class="text-base-foreground">
diff --git a/src/renderer/extensions/vueNodes/components/LGraphNode.vue b/src/renderer/extensions/vueNodes/components/LGraphNode.vue
index 0b79cc77909..fb6091a576c 100644
--- a/src/renderer/extensions/vueNodes/components/LGraphNode.vue
+++ b/src/renderer/extensions/vueNodes/components/LGraphNode.vue
@@ -304,6 +304,7 @@ import { applyLightThemeColor } from '@/renderer/extensions/vueNodes/utils/nodeS
 import { app } from '@/scripts/app'
 import { useMissingModelStore } from '@/platform/missingModel/missingModelStore'
 import { useExecutionErrorStore } from '@/stores/executionErrorStore'
+import { useMissingNodesErrorStore } from '@/platform/nodeReplacement/missingNodesErrorStore'
 import { useNodeOutputStore } from '@/stores/nodeOutputStore'
 import { useRightSidePanelStore } from '@/stores/workspace/rightSidePanelStore'
 import { isVideoOutput } from '@/utils/litegraphUtil'
@@ -355,6 +356,7 @@ const nodeLocatorId = computed(() => getLocatorIdFromNodeData(nodeData))
 const { executing, progress } = useNodeExecutionState(nodeLocatorId)
 const executionErrorStore = useExecutionErrorStore()
 const missingModelStore = useMissingModelStore()
+const missingNodesErrorStore = useMissingNodesErrorStore()
 const hasExecutionError = computed(
   () => executionErrorStore.lastExecutionErrorNodeId === nodeData.id
 )
@@ -368,7 +370,7 @@ const hasAnyError = computed((): boolean => {
     missingModelStore.hasMissingModelOnNode(nodeLocatorId.value) ||
     (lgraphNode.value &&
       (executionErrorStore.isContainerWithInternalError(lgraphNode.value) ||
-        executionErrorStore.isContainerWithMissingNode(lgraphNode.value) ||
+        missingNodesErrorStore.isContainerWithMissingNode(lgraphNode.value) ||
         missingModelStore.isContainerWithMissingModel(lgraphNode.value)))
   )
 })
diff --git a/src/scripts/app.ts b/src/scripts/app.ts
index e4e33911969..c0eff760dda 100644
--- a/src/scripts/app.ts
+++ b/src/scripts/app.ts
@@ -65,6 +65,7 @@ import { useCommandStore } from '@/stores/commandStore'
 import { useDomWidgetStore } from '@/stores/domWidgetStore'
 import { useExecutionStore } from '@/stores/executionStore'
 import { useExecutionErrorStore } from '@/stores/executionErrorStore'
+import { useMissingNodesErrorStore } from '@/platform/nodeReplacement/missingNodesErrorStore'
 import { useExtensionStore } from '@/stores/extensionStore'
 import { useFirebaseAuthStore } from '@/stores/firebaseAuthStore'
 import { useNodeOutputStore } from '@/stores/nodeOutputStore'
@@ -83,7 +84,7 @@ import type { ComfyExtension, MissingNodeType } from '@/types/comfy'
 import type { ExtensionManager } from '@/types/extensionTypes'
 import type { NodeExecutionId } from '@/types/nodeIdentification'
 import { graphToPrompt } from '@/utils/executionUtil'
-import { getCnrIdFromProperties } from '@/workbench/extensions/manager/utils/missingNodeErrorUtil'
+import { getCnrIdFromProperties } from '@/platform/nodeReplacement/cnrIdUtil'
 import { rescanAndSurfaceMissingNodes } from '@/platform/nodeReplacement/missingNodeScan'
 import {
   scanAllModelCandidates,
@@ -1105,7 +1106,9 @@ export class ComfyApp {
   }
 
   private showMissingNodesError(missingNodeTypes: MissingNodeType[]) {
-    useExecutionErrorStore().surfaceMissingNodes(missingNodeTypes)
+    if (useMissingNodesErrorStore().surfaceMissingNodes(missingNodeTypes)) {
+      useExecutionErrorStore().showErrorOverlay()
+    }
   }
 
   async loadGraphData(
diff --git a/src/stores/executionErrorStore.test.ts b/src/stores/executionErrorStore.test.ts
index 78beb43efde..10af3710a13 100644
--- a/src/stores/executionErrorStore.test.ts
+++ b/src/stores/executionErrorStore.test.ts
@@ -34,193 +34,7 @@ vi.mock(
 )
 
 import { useExecutionErrorStore } from './executionErrorStore'
-
-describe('executionErrorStore — missing node operations', () => {
-  beforeEach(() => {
-    setActivePinia(createPinia())
-  })
-
-  describe('setMissingNodeTypes', () => {
-    it('sets missingNodesError with provided types', () => {
-      const store = useExecutionErrorStore()
-      const types: MissingNodeType[] = [
-        { type: 'NodeA', nodeId: '1', isReplaceable: false }
-      ]
-      store.setMissingNodeTypes(types)
-
-      expect(store.missingNodesError).not.toBeNull()
-      expect(store.missingNodesError?.nodeTypes).toHaveLength(1)
-      expect(store.hasMissingNodes).toBe(true)
-    })
-
-    it('clears missingNodesError when given empty array', () => {
-      const store = useExecutionErrorStore()
-      store.setMissingNodeTypes([
-        { type: 'NodeA', nodeId: '1', isReplaceable: false }
-      ])
-      expect(store.missingNodesError).not.toBeNull()
-
-      store.setMissingNodeTypes([])
-      expect(store.missingNodesError).toBeNull()
-      expect(store.hasMissingNodes).toBe(false)
-    })
-
-    it('deduplicates string entries by value', () => {
-      const store = useExecutionErrorStore()
-      store.setMissingNodeTypes([
-        'NodeA',
-        'NodeA',
-        'NodeB'
-      ] as MissingNodeType[])
-
-      expect(store.missingNodesError?.nodeTypes).toHaveLength(2)
-    })
-
-    it('deduplicates object entries by nodeId when present', () => {
-      const store = useExecutionErrorStore()
-      store.setMissingNodeTypes([
-        { type: 'NodeA', nodeId: '1', isReplaceable: false },
-        { type: 'NodeA', nodeId: '1', isReplaceable: false },
-        { type: 'NodeA', nodeId: '2', isReplaceable: false }
-      ])
-
-      // Same nodeId='1' deduplicated, nodeId='2' kept
-      expect(store.missingNodesError?.nodeTypes).toHaveLength(2)
-    })
-
-    it('deduplicates object entries by type when nodeId is absent', () => {
-      const store = useExecutionErrorStore()
-      store.setMissingNodeTypes([
-        { type: 'NodeA', isReplaceable: false },
-        { type: 'NodeA', isReplaceable: true }
-      ] as MissingNodeType[])
-
-      // Same type, no nodeId → deduplicated
-      expect(store.missingNodesError?.nodeTypes).toHaveLength(1)
-    })
-
-    it('keeps distinct nodeIds even when type is the same', () => {
-      const store = useExecutionErrorStore()
-      store.setMissingNodeTypes([
-        { type: 'NodeA', nodeId: '1', isReplaceable: false },
-        { type: 'NodeA', nodeId: '2', isReplaceable: false },
-        { type: 'NodeA', nodeId: '3', isReplaceable: false }
-      ])
-
-      expect(store.missingNodesError?.nodeTypes).toHaveLength(3)
-    })
-  })
-
-  describe('surfaceMissingNodes', () => {
-    beforeEach(() => {
-      mockShowErrorsTab.value = false
-    })
-
-    it('stores missing node types when called', () => {
-      const store = useExecutionErrorStore()
-      const types: MissingNodeType[] = [
-        { type: 'NodeA', nodeId: '1', isReplaceable: false }
-      ]
-      store.surfaceMissingNodes(types)
-
-      expect(store.missingNodesError).not.toBeNull()
-      expect(store.missingNodesError?.nodeTypes).toHaveLength(1)
-      expect(store.hasMissingNodes).toBe(true)
-    })
-
-    it('opens error overlay when ShowErrorsTab setting is true', () => {
-      mockShowErrorsTab.value = true
-      const store = useExecutionErrorStore()
-      store.surfaceMissingNodes([
-        { type: 'NodeA', nodeId: '1', isReplaceable: false }
-      ])
-
-      expect(store.isErrorOverlayOpen).toBe(true)
-    })
-
-    it('does not open error overlay when ShowErrorsTab setting is false', () => {
-      mockShowErrorsTab.value = false
-      const store = useExecutionErrorStore()
-      store.surfaceMissingNodes([
-        { type: 'NodeA', nodeId: '1', isReplaceable: false }
-      ])
-
-      expect(store.isErrorOverlayOpen).toBe(false)
-    })
-
-    it('deduplicates node types', () => {
-      const store = useExecutionErrorStore()
-      store.surfaceMissingNodes([
-        { type: 'NodeA', nodeId: '1', isReplaceable: false },
-        { type: 'NodeA', nodeId: '1', isReplaceable: false },
-        { type: 'NodeB', nodeId: '2', isReplaceable: false }
-      ])
-
-      expect(store.missingNodesError?.nodeTypes).toHaveLength(2)
-    })
-  })
-
-  describe('removeMissingNodesByType', () => {
-    it('removes matching types from the missing nodes list', () => {
-      const store = useExecutionErrorStore()
-      store.setMissingNodeTypes([
-        { type: 'NodeA', nodeId: '1', isReplaceable: false },
-        { type: 'NodeB', nodeId: '2', isReplaceable: false },
-        { type: 'NodeC', nodeId: '3', isReplaceable: false }
-      ])
-
-      store.removeMissingNodesByType(['NodeA', 'NodeC'])
-
-      expect(store.missingNodesError?.nodeTypes).toHaveLength(1)
-      const remaining = store.missingNodesError?.nodeTypes[0]
-      expect(typeof remaining !== 'string' && remaining?.type).toBe('NodeB')
-    })
-
-    it('clears missingNodesError when all types are removed', () => {
-      const store = useExecutionErrorStore()
-      store.setMissingNodeTypes([
-        { type: 'NodeA', nodeId: '1', isReplaceable: false }
-      ])
-
-      store.removeMissingNodesByType(['NodeA'])
-
-      expect(store.missingNodesError).toBeNull()
-      expect(store.hasMissingNodes).toBe(false)
-    })
-
-    it('does nothing when missingNodesError is null', () => {
-      const store = useExecutionErrorStore()
-      expect(store.missingNodesError).toBeNull()
-
-      // Should not throw
-      store.removeMissingNodesByType(['NodeA'])
-      expect(store.missingNodesError).toBeNull()
-    })
-
-    it('does nothing when removing non-existent types', () => {
-      const store = useExecutionErrorStore()
-      store.setMissingNodeTypes([
-        { type: 'NodeA', nodeId: '1', isReplaceable: false }
-      ])
-
-      store.removeMissingNodesByType(['NonExistent'])
-
-      expect(store.missingNodesError?.nodeTypes).toHaveLength(1)
-    })
-
-    it('handles removing from string entries', () => {
-      const store = useExecutionErrorStore()
-      store.setMissingNodeTypes([
-        'StringNodeA',
-        'StringNodeB'
-      ] as MissingNodeType[])
-
-      store.removeMissingNodesByType(['StringNodeA'])
-
-      expect(store.missingNodesError?.nodeTypes).toHaveLength(1)
-    })
-  })
-})
+import { useMissingNodesErrorStore } from '@/platform/nodeReplacement/missingNodesErrorStore'
 
 describe('executionErrorStore — node error operations', () => {
   beforeEach(() => {
@@ -537,16 +351,18 @@ describe('executionErrorStore — node error operations', () => {
 })
 
 describe('clearAllErrors', () => {
-  let store: ReturnType<typeof useExecutionErrorStore>
+  let executionErrorStore: ReturnType<typeof useExecutionErrorStore>
+  let missingNodesStore: ReturnType<typeof useMissingNodesErrorStore>
 
   beforeEach(() => {
     const pinia = createPinia()
     setActivePinia(pinia)
-    store = useExecutionErrorStore()
+    executionErrorStore = useExecutionErrorStore()
+    missingNodesStore = useMissingNodesErrorStore()
   })
 
   it('resets all error categories and closes error overlay', () => {
-    store.lastExecutionError = {
+    executionErrorStore.lastExecutionError = {
       prompt_id: 'test',
       timestamp: 0,
       node_id: '1',
@@ -556,8 +372,12 @@ describe('clearAllErrors', () => {
       exception_type: 'RuntimeError',
       traceback: []
     }
-    store.lastPromptError = { type: 'execution', message: 'fail', details: '' }
-    store.lastNodeErrors = {
+    executionErrorStore.lastPromptError = {
+      type: 'execution',
+      message: 'fail',
+      details: ''
+    }
+    executionErrorStore.lastNodeErrors = {
       '1': {
         errors: [
           {
@@ -571,19 +391,18 @@ describe('clearAllErrors', () => {
         class_type: 'Test'
       }
     }
-    store.missingNodesError = {
-      message: 'Missing nodes',
-      nodeTypes: [{ type: 'MissingNode', hint: '' }]
-    }
-    store.showErrorOverlay()
-
-    store.clearAllErrors()
-
-    expect(store.lastExecutionError).toBeNull()
-    expect(store.lastPromptError).toBeNull()
-    expect(store.lastNodeErrors).toBeNull()
-    expect(store.missingNodesError).toBeNull()
-    expect(store.isErrorOverlayOpen).toBe(false)
-    expect(store.hasAnyError).toBe(false)
+    missingNodesStore.setMissingNodeTypes([
+      { type: 'MissingNode', hint: '' }
+    ] as unknown as MissingNodeType[])
+    executionErrorStore.showErrorOverlay()
+
+    executionErrorStore.clearAllErrors()
+
+    expect(executionErrorStore.lastExecutionError).toBeNull()
+    expect(executionErrorStore.lastPromptError).toBeNull()
+    expect(executionErrorStore.lastNodeErrors).toBeNull()
+    expect(missingNodesStore.missingNodesError).toBeNull()
+    expect(executionErrorStore.isErrorOverlayOpen).toBe(false)
+    expect(executionErrorStore.hasAnyError).toBe(false)
   })
 })
diff --git a/src/stores/executionErrorStore.ts b/src/stores/executionErrorStore.ts
index acff30deeea..478679c53b2 100644
--- a/src/stores/executionErrorStore.ts
+++ b/src/stores/executionErrorStore.ts
@@ -1,122 +1,43 @@
 import { defineStore } from 'pinia'
-import { computed, ref, watch } from 'vue'
+import { computed, ref } from 'vue'
 
-import { st } from '@/i18n'
-import { isCloud } from '@/platform/distribution/types'
-import { useCanvasStore } from '@/renderer/core/canvas/canvasStore'
+import { useNodeErrorFlagSync } from '@/composables/graph/useNodeErrorFlagSync'
+import type { LGraphNode } from '@/lib/litegraph/src/litegraph'
+import { useMissingModelStore } from '@/platform/missingModel/missingModelStore'
+import type { MissingModelCandidate } from '@/platform/missingModel/types'
 import { useSettingStore } from '@/platform/settings/settingStore'
 import { useWorkflowStore } from '@/platform/workflow/management/stores/workflowStore'
+import type { NodeId } from '@/platform/workflow/validation/schemas/workflowSchema'
+import { useCanvasStore } from '@/renderer/core/canvas/canvasStore'
 import { app } from '@/scripts/app'
 import type {
   ExecutionErrorWsMessage,
   NodeError,
   PromptError
 } from '@/schemas/apiSchema'
-import type { NodeId } from '@/platform/workflow/validation/schemas/workflowSchema'
-import { useMissingModelStore } from '@/platform/missingModel/missingModelStore'
-import type { MissingModelCandidate } from '@/platform/missingModel/types'
-import type { LGraph, LGraphNode } from '@/lib/litegraph/src/litegraph'
-import {
-  getAncestorExecutionIds,
-  getParentExecutionIds
-} from '@/types/nodeIdentification'
+import { getAncestorExecutionIds } from '@/types/nodeIdentification'
 import type { NodeExecutionId, NodeLocatorId } from '@/types/nodeIdentification'
-import type { MissingNodeType } from '@/types/comfy'
 import {
   executionIdToNodeLocatorId,
-  forEachNode,
-  getNodeByExecutionId,
   getExecutionIdByNode,
-  getActiveGraphNodeIds
+  getNodeByExecutionId
 } from '@/utils/graphTraversalUtil'
 import {
-  isValueStillOutOfRange,
-  SIMPLE_ERROR_TYPES
+  SIMPLE_ERROR_TYPES,
+  isValueStillOutOfRange
 } from '@/utils/executionErrorUtil'
-
-interface MissingNodesError {
-  message: string
-  nodeTypes: MissingNodeType[]
-}
-
-function setNodeHasErrors(node: LGraphNode, hasErrors: boolean): void {
-  if (node.has_errors === hasErrors) return
-  const oldValue = node.has_errors
-  node.has_errors = hasErrors
-  node.graph?.trigger('node:property:changed', {
-    type: 'node:property:changed',
-    nodeId: node.id,
-    property: 'has_errors',
-    oldValue,
-    newValue: hasErrors
-  })
-}
-
-/**
- * Single-pass reconciliation of node error flags.
- * Collects the set of nodes that should have errors, then walks all nodes
- * once, setting each flag exactly once. This avoids the redundant
- * true→false→true transition (and duplicate events) that a clear-then-apply
- * approach would cause.
- */
-function reconcileNodeErrorFlags(
-  rootGraph: LGraph,
-  nodeErrors: Record<string, NodeError> | null,
-  missingModelExecIds: Set<string>
-): void {
-  // Collect nodes and slot info that should be flagged
-  // Includes both error-owning nodes and their ancestor containers
-  const flaggedNodes = new Set<LGraphNode>()
-  const errorSlots = new Map<LGraphNode, Set<string>>()
-
-  if (nodeErrors) {
-    for (const [executionId, nodeError] of Object.entries(nodeErrors)) {
-      const node = getNodeByExecutionId(rootGraph, executionId)
-      if (!node) continue
-
-      flaggedNodes.add(node)
-      const slotNames = new Set<string>()
-      for (const error of nodeError.errors) {
-        const name = error.extra_info?.input_name
-        if (name) slotNames.add(name)
-      }
-      if (slotNames.size > 0) errorSlots.set(node, slotNames)
-
-      for (const parentId of getParentExecutionIds(executionId)) {
-        const parentNode = getNodeByExecutionId(rootGraph, parentId)
-        if (parentNode) flaggedNodes.add(parentNode)
-      }
-    }
-  }
-
-  for (const execId of missingModelExecIds) {
-    const node = getNodeByExecutionId(rootGraph, execId)
-    if (node) flaggedNodes.add(node)
-  }
-
-  forEachNode(rootGraph, (node) => {
-    setNodeHasErrors(node, flaggedNodes.has(node))
-
-    if (node.inputs) {
-      const nodeSlotNames = errorSlots.get(node)
-      for (const slot of node.inputs) {
-        slot.hasErrors = !!nodeSlotNames?.has(slot.name)
-      }
-    }
-  })
-}
+import { useMissingNodesErrorStore } from '@/platform/nodeReplacement/missingNodesErrorStore'
 
 /** Execution error state: node errors, runtime errors, prompt errors, and missing assets. */
 export const useExecutionErrorStore = defineStore('executionError', () => {
   const workflowStore = useWorkflowStore()
   const canvasStore = useCanvasStore()
-
   const missingModelStore = useMissingModelStore()
+  const missingNodesStore = useMissingNodesErrorStore()
 
   const lastNodeErrors = ref<Record<NodeId, NodeError> | null>(null)
   const lastExecutionError = ref<ExecutionErrorWsMessage | null>(null)
   const lastPromptError = ref<PromptError | null>(null)
-  const missingNodesError = ref<MissingNodesError | null>(null)
 
   const isErrorOverlayOpen = ref(false)
 
@@ -136,7 +57,7 @@ export const useExecutionErrorStore = defineStore('executionError', () => {
     lastExecutionError.value = null
     lastPromptError.value = null
     lastNodeErrors.value = null
-    missingNodesError.value = null
+    missingNodesStore.setMissingNodeTypes([])
     isErrorOverlayOpen.value = false
   }
 
@@ -238,14 +159,6 @@ export const useExecutionErrorStore = defineStore('executionError', () => {
     missingModelStore.removeMissingModelByWidget(executionId, widgetName)
   }
 
-  /** Set missing node types and open the error overlay if the Errors tab is enabled. */
-  function surfaceMissingNodes(types: MissingNodeType[]) {
-    setMissingNodeTypes(types)
-    if (useSettingStore().get('Comfy.RightSidePanel.ShowErrorsTab')) {
-      showErrorOverlay()
-    }
-  }
-
   /** Set missing models and open the error overlay if the Errors tab is enabled. */
   function surfaceMissingModels(models: MissingModelCandidate[]) {
     missingModelStore.setMissingModels(models)
@@ -257,51 +170,6 @@ export const useExecutionErrorStore = defineStore('executionError', () => {
     }
   }
 
-  /** Remove specific node types from the missing nodes list (e.g. after replacement). */
-  function removeMissingNodesByType(typesToRemove: string[]) {
-    if (!missingNodesError.value) return
-    const removeSet = new Set(typesToRemove)
-    const remaining = missingNodesError.value.nodeTypes.filter((node) => {
-      const nodeType = typeof node === 'string' ? node : node.type
-      return !removeSet.has(nodeType)
-    })
-    setMissingNodeTypes(remaining)
-  }
-
-  function setMissingNodeTypes(types: MissingNodeType[]) {
-    if (!types.length) {
-      missingNodesError.value = null
-      return
-    }
-    const seen = new Set<string>()
-    const uniqueTypes = types.filter((node) => {
-      // For string entries (group nodes), deduplicate by the string itself.
-      // For object entries, prefer nodeId so multiple instances of the same
-      // type are kept as separate rows; fall back to type if nodeId is absent.
-      const isString = typeof node === 'string'
-      let key: string
-      if (isString) {
-        key = node
-      } else if (node.nodeId != null) {
-        key = String(node.nodeId)
-      } else {
-        key = node.type
-      }
-      if (seen.has(key)) return false
-      seen.add(key)
-      return true
-    })
-    missingNodesError.value = {
-      message: isCloud
-        ? st(
-            'rightSidePanel.missingNodePacks.unsupportedTitle',
-            'Unsupported Node Packs'
-          )
-        : st('rightSidePanel.missingNodePacks.title', 'Missing Node Packs'),
-      nodeTypes: uniqueTypes
-    }
-  }
-
   const lastExecutionErrorNodeLocatorId = computed(() => {
     const err = lastExecutionError.value
     if (!err) return null
@@ -323,14 +191,12 @@ export const useExecutionErrorStore = defineStore('executionError', () => {
     () => !!lastNodeErrors.value && Object.keys(lastNodeErrors.value).length > 0
   )
 
-  const hasMissingNodes = computed(() => !!missingNodesError.value)
-
   const hasAnyError = computed(
     () =>
       hasExecutionError.value ||
       hasPromptError.value ||
       hasNodeError.value ||
-      hasMissingNodes.value ||
+      missingNodesStore.hasMissingNodes ||
       missingModelStore.hasMissingModels
   )
 
@@ -361,14 +227,12 @@ export const useExecutionErrorStore = defineStore('executionError', () => {
 
   const executionErrorCount = computed(() => (lastExecutionError.value ? 1 : 0))
 
-  const missingNodeCount = computed(() => (missingNodesError.value ? 1 : 0))
-
   const totalErrorCount = computed(
     () =>
       promptErrorCount.value +
       nodeErrorCount.value +
       executionErrorCount.value +
-      missingNodeCount.value +
+      missingNodesStore.missingNodeCount +
       missingModelStore.missingModelCount
   )
 
@@ -400,37 +264,6 @@ export const useExecutionErrorStore = defineStore('executionError', () => {
     return ids
   })
 
-  /**
-   * Set of all execution ID prefixes derived from missing node execution IDs,
-   * including the missing nodes themselves.
-   *
-   * Example: missing node at "65:70:63" → Set { "65", "65:70", "65:70:63" }
-   */
-  const missingAncestorExecutionIds = computed<Set<NodeExecutionId>>(() => {
-    const ids = new Set<NodeExecutionId>()
-    const error = missingNodesError.value
-    if (!error) return ids
-
-    for (const nodeType of error.nodeTypes) {
-      if (typeof nodeType === 'string') continue
-      if (nodeType.nodeId == null) continue
-      for (const id of getAncestorExecutionIds(String(nodeType.nodeId))) {
-        ids.add(id)
-      }
-    }
-
-    return ids
-  })
-
-  const activeMissingNodeGraphIds = computed<Set<string>>(() => {
-    if (!app.isGraphReady) return new Set()
-    return getActiveGraphNodeIds(
-      app.rootGraph,
-      canvasStore.currentGraph ?? app.rootGraph,
-      missingAncestorExecutionIds.value
-    )
-  })
-
   /** Map of node errors indexed by locator ID. */
   const nodeErrorsByLocatorId = computed<Record<NodeLocatorId, NodeError>>(
     () => {
@@ -493,42 +326,13 @@ export const useExecutionErrorStore = defineStore('executionError', () => {
     return errorAncestorExecutionIds.value.has(execId)
   }
 
-  /** True if the node has a missing node inside it at any nesting depth. */
-  function isContainerWithMissingNode(node: LGraphNode): boolean {
-    if (!app.isGraphReady) return false
-    const execId = getExecutionIdByNode(app.rootGraph, node)
-    if (!execId) return false
-    return missingAncestorExecutionIds.value.has(execId)
-  }
-
-  watch(
-    [lastNodeErrors, () => missingModelStore.missingModelNodeIds],
-    () => {
-      if (!app.isGraphReady) return
-      // Legacy (LGraphNode) only: suppress missing-model error flags when
-      // the Errors tab is hidden, since legacy nodes lack the per-widget
-      // red highlight that Vue nodes use to indicate *why* a node has errors.
-      // Vue nodes compute hasAnyError independently and are unaffected.
-      const showErrorsTab = useSettingStore().get(
-        'Comfy.RightSidePanel.ShowErrorsTab'
-      )
-      reconcileNodeErrorFlags(
-        app.rootGraph,
-        lastNodeErrors.value,
-        showErrorsTab
-          ? missingModelStore.missingModelAncestorExecutionIds
-          : new Set()
-      )
-    },
-    { flush: 'post' }
-  )
+  useNodeErrorFlagSync(lastNodeErrors, missingModelStore)
 
   return {
     // Raw state
     lastNodeErrors,
     lastExecutionError,
     lastPromptError,
-    missingNodesError,
 
     // Clearing
     clearAllErrors,
@@ -543,30 +347,22 @@ export const useExecutionErrorStore = defineStore('executionError', () => {
     hasExecutionError,
     hasPromptError,
     hasNodeError,
-    hasMissingNodes,
     hasAnyError,
     allErrorExecutionIds,
     totalErrorCount,
     lastExecutionErrorNodeId,
     activeGraphErrorNodeIds,
-    activeMissingNodeGraphIds,
 
     // Clearing (targeted)
     clearSimpleNodeErrors,
     clearWidgetRelatedErrors,
 
-    // Missing node actions
-    setMissingNodeTypes,
-    surfaceMissingNodes,
-    removeMissingNodesByType,
-
     // Missing model coordination (delegates to missingModelStore)
     surfaceMissingModels,
 
     // Lookup helpers
     getNodeErrors,
     slotHasError,
-    isContainerWithInternalError,
-    isContainerWithMissingNode
+    isContainerWithInternalError
   }
 })
diff --git a/src/stores/executionStore.test.ts b/src/stores/executionStore.test.ts
index e208b452f39..cf531463d4e 100644
--- a/src/stores/executionStore.test.ts
+++ b/src/stores/executionStore.test.ts
@@ -3,6 +3,7 @@ import { beforeEach, describe, expect, it, vi } from 'vitest'
 import { app } from '@/scripts/app'
 import { MAX_PROGRESS_JOBS, useExecutionStore } from '@/stores/executionStore'
 import { useExecutionErrorStore } from '@/stores/executionErrorStore'
+import { useMissingNodesErrorStore } from '@/platform/nodeReplacement/missingNodesErrorStore'
 import { executionIdToNodeLocatorId } from '@/utils/graphTraversalUtil'
 
 // Create mock functions that will be shared
@@ -598,13 +599,13 @@ describe('useExecutionErrorStore - Node Error Lookups', () => {
   })
 })
 
-describe('useExecutionErrorStore - setMissingNodeTypes', () => {
-  let store: ReturnType<typeof useExecutionErrorStore>
+describe('useMissingNodesErrorStore - setMissingNodeTypes', () => {
+  let store: ReturnType<typeof useMissingNodesErrorStore>
 
   beforeEach(() => {
     vi.clearAllMocks()
     setActivePinia(createTestingPinia({ stubActions: false }))
-    store = useExecutionErrorStore()
+    store = useMissingNodesErrorStore()
   })
 
   it('clears missingNodesError when called with an empty array', () => {