diff --git a/ui/desktop/src/components/pair.tsx b/ui/desktop/src/components/pair.tsx
index 0aa7353ab55a..45504c096d19 100644
--- a/ui/desktop/src/components/pair.tsx
+++ b/ui/desktop/src/components/pair.tsx
@@ -62,12 +62,58 @@ export default function Pair({
           return prev;
         });
       } catch (error) {
-        console.log(error);
-        setFatalError(`Agent init failure: ${error instanceof Error ? error.message : '' + error}`);
+        console.error('Agent initialization failed:', error);
+
+        // Clear deleted session from URL and retry
+        if (
+          error instanceof Error &&
+          (error.message.includes('Session not found') || error.message.includes('404'))
+        ) {
+          console.log('Clearing invalid session ID from URL');
+          setSearchParams((prev) => {
+            prev.delete('resumeSessionId');
+            return prev;
+          });
+
+          try {
+            const chat = await loadCurrentChat({
+              setAgentWaitingMessage,
+            });
+            setChat(chat);
+            setSearchParams((prev) => {
+              prev.set('resumeSessionId', chat.sessionId);
+              return prev;
+            });
+          } catch (retryError) {
+            handleInitializationError(retryError);
+          }
+        } else {
+          handleInitializationError(error);
+        }
       } finally {
         setLoadingChat(false);
       }
     };
+
+    const handleInitializationError = (error: unknown) => {
+      let errorMessage = 'Unknown error occurred';
+      if (error) {
+        if (error instanceof Error) {
+          errorMessage = error.message;
+        } else if (typeof error === 'object' && error !== null) {
+          // Handle case where error is an object with properties
+          try {
+            errorMessage = JSON.stringify(error);
+          } catch {
+            errorMessage = Object.prototype.toString.call(error);
+          }
+        } else {
+          errorMessage = String(error);
+        }
+      }
+      setFatalError(`Agent init failure: ${errorMessage}`);
+    };
+
     initializeFromState();
   }, [
     agentState,
diff --git a/ui/desktop/src/hooks/useAgent.ts b/ui/desktop/src/hooks/useAgent.ts
index 136554ab4cee..37fea45d973c 100644
--- a/ui/desktop/src/hooks/useAgent.ts
+++ b/ui/desktop/src/hooks/useAgent.ts
@@ -47,6 +47,7 @@ export function useAgent(): UseAgentReturn {
   const [agentState, setAgentState] = useState<AgentState>(AgentState.UNINITIALIZED);
   const [sessionId, setSessionId] = useState<string | null>(null);
   const initPromiseRef = useRef<Promise<ChatType> | null>(null);
+  const deletedSessionsRef = useRef<Set<string>>(new Set());
   const recipeIdFromConfig = useRef<string | null>(
     (window.appConfig.get('recipeId') as string | null | undefined) ?? null
   );
@@ -64,30 +65,65 @@ export function useAgent(): UseAgentReturn {
     recipeIdFromConfig.current = null;
     recipeDeeplinkFromConfig.current = null;
     scheduledJobIdFromConfig.current = null;
+    deletedSessionsRef.current.clear();
   }, []);
 
   const agentIsInitialized = agentState === AgentState.INITIALIZED;
   const currentChat = useCallback(
     async (initContext: InitializationContext): Promise<ChatType> => {
-      if (agentIsInitialized && sessionId) {
-        const agentResponse = await resumeAgent({
-          body: {
-            session_id: sessionId,
-            load_model_and_extensions: false,
-          },
-          throwOnError: true,
-        });
-
-        const agentSession = agentResponse.data;
-        const messages = agentSession.conversation || [];
-        return {
-          sessionId: agentSession.id,
-          name: agentSession.recipe?.title || agentSession.name,
-          messageHistoryIndex: 0,
-          messages,
-          recipe: agentSession.recipe,
-          recipeParameterValues: agentSession.user_recipe_values || null,
-        };
+      // Skip deleted sessions
+      if (
+        initContext.resumeSessionId &&
+        deletedSessionsRef.current.has(initContext.resumeSessionId)
+      ) {
+        initContext.resumeSessionId = undefined;
+
+        // Clear from URL
+        const url = new URL(window.location.href);
+        url.searchParams.delete('resumeSessionId');
+        window.history.replaceState({}, '', url.toString());
+      }
+
+      if (sessionId && deletedSessionsRef.current.has(sessionId)) {
+        setSessionId(null);
+      }
+
+      if (agentIsInitialized && sessionId && !deletedSessionsRef.current.has(sessionId)) {
+        let agentResponse;
+        try {
+          agentResponse = await resumeAgent({
+            body: {
+              session_id: sessionId,
+              load_model_and_extensions: false,
+            },
+            throwOnError: true,
+          });
+        } catch {
+          // Mark session as deleted and clear state
+          deletedSessionsRef.current.add(sessionId);
+          setSessionId(null);
+
+          // Clear from URL
+          const url = new URL(window.location.href);
+          if (url.searchParams.get('resumeSessionId')) {
+            url.searchParams.delete('resumeSessionId');
+            window.history.replaceState({}, '', url.toString());
+          }
+        }
+
+        // Fall through to create new session
+        if (agentResponse?.data) {
+          const agentSession = agentResponse.data;
+          const messages = agentSession.conversation || [];
+          return {
+            sessionId: agentSession.id,
+            name: agentSession.recipe?.title || agentSession.name,
+            messageHistoryIndex: 0,
+            messages,
+            recipe: agentSession.recipe,
+            recipeParameterValues: agentSession.user_recipe_values || null,
+          };
+        }
       }
 
       if (initPromiseRef.current) {
@@ -109,15 +145,38 @@ export function useAgent(): UseAgentReturn {
             throw new NoProviderOrModelError();
           }
 
-          const agentResponse = initContext.resumeSessionId
-            ? await resumeAgent({
-                body: {
-                  session_id: initContext.resumeSessionId,
-                  load_model_and_extensions: false,
-                },
-                throwOnError: true,
-              })
-            : await startAgent({
+          let agentResponse;
+          try {
+            agentResponse = initContext.resumeSessionId
+              ? await resumeAgent({
+                  body: {
+                    session_id: initContext.resumeSessionId,
+                    load_model_and_extensions: false,
+                  },
+                  throwOnError: true,
+                })
+              : await startAgent({
+                  body: {
+                    working_dir: window.appConfig.get('GOOSE_WORKING_DIR') as string,
+                    ...buildRecipeInput(
+                      initContext.recipe,
+                      recipeIdFromConfig.current,
+                      recipeDeeplinkFromConfig.current
+                    ),
+                  },
+                  throwOnError: true,
+                });
+          } catch (error) {
+            // If resuming fails, mark session as deleted and create new agent
+            if (initContext.resumeSessionId) {
+              deletedSessionsRef.current.add(initContext.resumeSessionId);
+
+              // Clear from URL
+              const url = new URL(window.location.href);
+              url.searchParams.delete('resumeSessionId');
+              window.history.replaceState({}, '', url.toString());
+
+              agentResponse = await startAgent({
                 body: {
                   working_dir: window.appConfig.get('GOOSE_WORKING_DIR') as string,
                   ...buildRecipeInput(
@@ -129,6 +188,13 @@ export function useAgent(): UseAgentReturn {
                 throwOnError: true,
               });
 
+              // Clear resume flag
+              initContext.resumeSessionId = undefined;
+            } else {
+              throw error;
+            }
+          }
+
           const agentSession = agentResponse.data;
           if (!agentSession) {
             throw Error('Failed to get session info');