diff --git a/src/constants.js b/src/constants.js
index 80e7cdd778..a23758cefb 100644
--- a/src/constants.js
+++ b/src/constants.js
@@ -81,3 +81,5 @@ export const REGEX_RULES = {
 export const IFRAME_FEATURE_POLICY = (
   'microphone *; camera *; midi *; geolocation *; encrypted-media *; clipboard-write *'
 );
+
+export const MULTI_LEVEL_XBLOCKS = ['conditional', 'problem-builder', 'step-builder'];
diff --git a/src/library-authoring/add-content/AddContentContainer.test.tsx b/src/library-authoring/add-content/AddContentContainer.test.tsx
index 229948c39e..b4c38aa24d 100644
--- a/src/library-authoring/add-content/AddContentContainer.test.tsx
+++ b/src/library-authoring/add-content/AddContentContainer.test.tsx
@@ -238,10 +238,23 @@ describe('<AddContentContainer />', () => {
     const pasteButton = await screen.findByRole('button', { name: /paste from clipboard/i });
     fireEvent.click(pasteButton);
 
-    await waitFor(() => {
-      expect(axiosMock.history.post.length).toEqual(0);
-      expect(mockShowToast).toHaveBeenCalledWith(errMsg);
-    });
+    await waitFor(() => expect(axiosMock.history.post.length).toEqual(0));
+    await waitFor(() => expect(mockShowToast).toHaveBeenCalledWith(errMsg));
+  });
+
+  it('should stop user from pasting multilevel blocks and show toast', async () => {
+    // Simulate having an HTML block in the clipboard:
+    mockClipboardHtml.applyMock('conditional');
+
+    const errMsg = 'Libraries do not support this type of content yet.';
+
+    render();
+
+    const pasteButton = await screen.findByRole('button', { name: /paste from clipboard/i });
+    fireEvent.click(pasteButton);
+
+    await waitFor(() => expect(axiosMock.history.post.length).toEqual(0));
+    await waitFor(() => expect(mockShowToast).toHaveBeenCalledWith(errMsg));
   });
 
   test.each([
diff --git a/src/library-authoring/add-content/AddContentContainer.tsx b/src/library-authoring/add-content/AddContentContainer.tsx
index 1a2e28b1a9..995695134e 100644
--- a/src/library-authoring/add-content/AddContentContainer.tsx
+++ b/src/library-authoring/add-content/AddContentContainer.tsx
@@ -30,6 +30,7 @@ import { canEditComponent } from '../components/ComponentEditorModal';
 import { PickLibraryContentModal } from './PickLibraryContentModal';
 
 import messages from './messages';
+import { MULTI_LEVEL_XBLOCKS } from '../../constants';
 
 type ContentType = {
   name: string,
@@ -78,7 +79,6 @@ const AddContentContainer = () => {
   const { showToast } = useContext(ToastContext);
   const canEdit = useSelector(getCanEdit);
   const { showPasteXBlock, sharedClipboardData } = useCopyToClipboard(canEdit);
-
   const [isAddLibraryContentModalOpen, showAddLibraryContentModal, closeAddLibraryContentModal] = useToggle();
 
   const parseErrorMsg = (
@@ -98,7 +98,13 @@ const AddContentContainer = () => {
     return intl.formatMessage(defaultMessage);
   };
 
-  const isBlockTypeEnabled = (blockType: string) => getConfig().LIBRARY_SUPPORTED_BLOCKS.includes(blockType);
+  const isBlockTypeEnabled = (blockType: string) => {
+    // For now multilevel blocks are not supported in libraries
+    if (MULTI_LEVEL_XBLOCKS.includes(blockType)) {
+      return false;
+    }
+    return getConfig().LIBRARY_SUPPORTED_BLOCKS.includes(blockType);
+  };
 
   const collectionButtonData = {
     name: intl.formatMessage(messages.collectionButton),
diff --git a/src/library-authoring/component-info/ComponentInfo.test.tsx b/src/library-authoring/component-info/ComponentInfo.test.tsx
index 6ccebc29fe..fce6f2d21e 100644
--- a/src/library-authoring/component-info/ComponentInfo.test.tsx
+++ b/src/library-authoring/component-info/ComponentInfo.test.tsx
@@ -60,6 +60,17 @@ describe('<ComponentInfo> Sidebar', () => {
     expect(screen.queryByRole('button', { name: /Edit component/ })).not.toBeInTheDocument();
   });
 
+  it('should show a disabled "Edit" button when the component type is multilevel', async () => {
+    initializeMocks();
+    render(
+      <ComponentInfo />,
+      withLibraryId(mockContentLibrary.libraryId, mockLibraryBlockMetadata.usageKeyMultiLevelXBlock),
+    );
+
+    const editButton = await screen.findByRole('button', { name: /Edit component/ });
+    expect(editButton).toBeDisabled();
+  });
+
   it('should show a working "Edit" button for a normal component', async () => {
     initializeMocks();
     render(
diff --git a/src/library-authoring/components/ComponentEditorModal.tsx b/src/library-authoring/components/ComponentEditorModal.tsx
index e139a8c409..fd94b9189e 100644
--- a/src/library-authoring/components/ComponentEditorModal.tsx
+++ b/src/library-authoring/components/ComponentEditorModal.tsx
@@ -6,6 +6,7 @@ import EditorPage from '../../editors/EditorPage';
 import { getBlockType } from '../../generic/key-utils';
 import { useLibraryContext } from '../common/context/LibraryContext';
 import { invalidateComponentData } from '../data/apiHooks';
+import { MULTI_LEVEL_XBLOCKS } from '../../constants';
 
 export function canEditComponent(usageKey: string): boolean {
   let blockType: string;
@@ -15,6 +16,11 @@ export function canEditComponent(usageKey: string): boolean {
     return false;
   }
 
+  // For now multilevel blocks are not supported in libraries
+  if (MULTI_LEVEL_XBLOCKS.includes(blockType)) {
+    return false;
+  }
+
   return getConfig().LIBRARY_SUPPORTED_BLOCKS.includes(blockType);
 }
 
diff --git a/src/library-authoring/data/api.mocks.ts b/src/library-authoring/data/api.mocks.ts
index ce4be29168..268565d3ea 100644
--- a/src/library-authoring/data/api.mocks.ts
+++ b/src/library-authoring/data/api.mocks.ts
@@ -269,6 +269,7 @@ export async function mockXBlockFields(usageKey: string): Promise<api.XBlockFiel
     case thisMock.usageKeyNewProblem: return thisMock.dataNewProblem;
     case thisMock.usageKeyNewVideo: return thisMock.dataNewVideo;
     case thisMock.usageKeyThirdParty: return thisMock.dataThirdParty;
+    case thisMock.usageKeyMultiLevel: return thisMock.dataMultiLevel;
     default: throw new Error(`No mock has been set up for usageKey "${usageKey}"`);
   }
 }
@@ -305,6 +306,12 @@ mockXBlockFields.dataThirdParty = {
   data: '',
   metadata: { displayName: 'Third party XBlock' },
 } satisfies api.XBlockFields;
+mockXBlockFields.usageKeyMultiLevel = 'lb:Axim:TEST:conditional:12345';
+mockXBlockFields.dataMultiLevel = {
+  displayName: 'Conditional (Multilevel) Block',
+  data: '',
+  metadata: { displayName: 'Conditional (Multilevel) Block' },
+} satisfies api.XBlockFields;
 /** Apply this mock. Returns a spy object that can tell you if it's been called. */
 mockXBlockFields.applyMock = () => jest.spyOn(api, 'getXBlockFields').mockImplementation(mockXBlockFields);
 
@@ -378,6 +385,12 @@ mockLibraryBlockMetadata.dataThirdPartyXBlock = {
   id: mockLibraryBlockMetadata.usageKeyThirdPartyXBlock,
   blockType: 'third_party',
 } satisfies api.LibraryBlockMetadata;
+mockLibraryBlockMetadata.usageKeyMultiLevelXBlock = mockXBlockFields.usageKeyMultiLevel;
+mockLibraryBlockMetadata.dataMultiLevelXBlock = {
+  ...mockLibraryBlockMetadata.dataPublished,
+  id: mockLibraryBlockMetadata.usageKeyMultiLevelXBlock,
+  blockType: 'conditional',
+} satisfies api.LibraryBlockMetadata;
 mockLibraryBlockMetadata.usageKeyForTags = mockContentTaxonomyTagsData.largeTagsId;
 mockLibraryBlockMetadata.usageKeyWithCollections = 'lb:Axim:TEST:html:571fe018-f3ce-45c9-8f53-5dafcb422fdd';
 mockLibraryBlockMetadata.dataWithCollections = {