Fix

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/components/action-bar/action-bar.tsx

@@ -168,11 +168,11 @@ export const ActionBar = memo(
             </Tooltip.Trigger>
             <Tooltip.Content side='top'>
               {(() => {
-                if (disabled) return getTooltipMessage('Run from this block')
+                if (disabled) return getTooltipMessage('Run from block')
                 if (isExecuting) return 'Execution in progress'
                 if (isInsideSubflow) return 'Cannot run from inside subflow'
                 if (!dependenciesSatisfied) return 'Run upstream blocks first'
-                return 'Run from this block'
+                return 'Run from block'
               })()}
             </Tooltip.Content>
           </Tooltip.Root>

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/components/block-menu/block-menu.tsx

@@ -46,8 +46,6 @@ export interface BlockMenuProps {
   showRemoveFromSubflow?: boolean
   /** Whether run from block is available (has snapshot, was executed, not inside subflow) */
   canRunFromBlock?: boolean
-  /** Reason why run from block is disabled (for tooltip) */
-  runFromBlockDisabledReason?: string
   disableEdit?: boolean
   isExecuting?: boolean
 }
@@ -77,7 +75,6 @@ export function BlockMenu({
   hasClipboard = false,
   showRemoveFromSubflow = false,
   canRunFromBlock = false,
-  runFromBlockDisabledReason,
   disableEdit = false,
   isExecuting = false,
 }: BlockMenuProps) {
@@ -228,11 +225,7 @@ export function BlockMenu({
                 }
               }}
             >
-              {isExecuting
-                ? 'Execution in progress...'
-                : !canRunFromBlock && runFromBlockDisabledReason
-                  ? runFromBlockDisabledReason
-                  : 'Run from this block'}
+              Run from block
             </PopoverItem>
             <PopoverItem
               disabled={isExecuting}
@@ -243,7 +236,7 @@ export function BlockMenu({
                 }
               }}
             >
-              {isExecuting ? 'Execution in progress...' : 'Run until this block'}
+              Run until block
             </PopoverItem>
           </>
         )}

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/hooks/use-workflow-execution.ts

@@ -23,6 +23,7 @@ import { subscriptionKeys } from '@/hooks/queries/subscription'
 import { useExecutionStream } from '@/hooks/use-execution-stream'
 import { WorkflowValidationError } from '@/serializer'
 import { useExecutionStore } from '@/stores/execution'
+import { useNotificationStore } from '@/stores/notifications'
 import { useVariablesStore } from '@/stores/panel'
 import { useEnvironmentStore } from '@/stores/settings/environment'
 import { type ConsoleEntry, useTerminalConsoleStore } from '@/stores/terminal'
@@ -101,11 +102,13 @@ export function useWorkflowExecution() {
     setEdgeRunStatus,
     setLastExecutionSnapshot,
     getLastExecutionSnapshot,
+    clearLastExecutionSnapshot,
   } = useExecutionStore()
   const [executionResult, setExecutionResult] = useState<ExecutionResult | null>(null)
   const executionStream = useExecutionStream()
   const currentChatExecutionIdRef = useRef<string | null>(null)
   const isViewingDiff = useWorkflowDiffStore((state) => state.isShowingDiff)
+  const addNotification = useNotificationStore((state) => state.addNotification)
 
   /**
    * Validates debug state before performing debug operations
@@ -1620,6 +1623,23 @@ export function useWorkflowExecution() {
 
             onExecutionError: (data) => {
               logger.error('Run-from-block execution error:', data.error)
+
+              // If block not found, the snapshot is stale - clear it
+              if (data.error?.includes('Block not found in workflow')) {
+                clearLastExecutionSnapshot(workflowId)
+                addNotification({
+                  level: 'info',
+                  message: 'Workflow was modified. Run the workflow again to refresh.',
+                  workflowId,
+                })
+                logger.info('Cleared stale execution snapshot', { workflowId })
+              } else {
+                addNotification({
+                  level: 'error',
+                  message: data.error || 'Run from block failed',
+                  workflowId,
+                })
+              }
             },
 
             onExecutionCancelled: () => {
@@ -1639,10 +1659,12 @@ export function useWorkflowExecution() {
     [
       getLastExecutionSnapshot,
       setLastExecutionSnapshot,
+      clearLastExecutionSnapshot,
       setIsExecuting,
       setActiveBlocks,
       setBlockRunStatus,
       setEdgeRunStatus,
+      addNotification,
       addConsole,
       executionStream,
     ]

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/workflow.tsx

@@ -3356,7 +3356,6 @@ const WorkflowContent = React.memo(() => {
                 (b) => b.parentId && (b.parentType === 'loop' || b.parentType === 'parallel')
               )}
               canRunFromBlock={runFromBlockState.canRun}
-              runFromBlockDisabledReason={runFromBlockState.reason}
               disableEdit={!effectivePermissions.canEdit}
               isExecuting={isExecuting}
             />