diff --git a/src/components/actionbar/ComfyRunButton/ComfyQueueButton.vue b/src/components/actionbar/ComfyRunButton/ComfyQueueButton.vue
index 8907ecf44..2b57b2439 100644
--- a/src/components/actionbar/ComfyRunButton/ComfyQueueButton.vue
+++ b/src/components/actionbar/ComfyRunButton/ComfyQueueButton.vue
@@ -2,9 +2,7 @@
   <div class="queue-button-group flex">
     <SplitButton
       v-tooltip.bottom="{
-        value: workspaceStore.shiftDown
-          ? $t('menu.runWorkflowFront')
-          : $t('menu.runWorkflow'),
+        value: queueButtonTooltip,
         showDelay: 600
       }"
       class="comfyui-queue-button"
@@ -12,20 +10,12 @@
       severity="primary"
       size="small"
       :model="queueModeMenuItems"
+      :disabled="hasMissingNodes"
       data-testid="queue-button"
       @click="queuePrompt"
     >
       <template #icon>
-        <i v-if="workspaceStore.shiftDown" class="icon-[lucide--list-start]" />
-        <i v-else-if="queueMode === 'disabled'" class="icon-[lucide--play]" />
-        <i
-          v-else-if="queueMode === 'instant'"
-          class="icon-[lucide--fast-forward]"
-        />
-        <i
-          v-else-if="queueMode === 'change'"
-          class="icon-[lucide--step-forward]"
-        />
+        <i :class="iconClass" />
       </template>
       <template #item="{ item }">
         <Button
@@ -95,6 +85,7 @@ import {
   useQueueSettingsStore
 } from '@/stores/queueStore'
 import { useWorkspaceStore } from '@/stores/workspaceStore'
+import { useMissingNodes } from '@/workbench/extensions/manager/composables/nodePack/useMissingNodes'
 
 import BatchCountEdit from '../BatchCountEdit.vue'
 
@@ -102,6 +93,8 @@ const workspaceStore = useWorkspaceStore()
 const queueCountStore = storeToRefs(useQueuePendingTaskCountStore())
 const { mode: queueMode, batchCount } = storeToRefs(useQueueSettingsStore())
 
+const { hasMissingNodes } = useMissingNodes()
+
 const { t } = useI18n()
 const queueModeMenuItemLookup = computed(() => {
   const items: Record<string, MenuItem> = {
@@ -157,6 +150,35 @@ const hasPendingTasks = computed(
   () => queueCountStore.count.value > 1 || queueMode.value !== 'disabled'
 )
 
+const iconClass = computed(() => {
+  if (hasMissingNodes.value) {
+    return 'icon-[lucide--triangle-alert]'
+  }
+  if (workspaceStore.shiftDown) {
+    return 'icon-[lucide--list-start]'
+  }
+  if (queueMode.value === 'disabled') {
+    return 'icon-[lucide--play]'
+  }
+  if (queueMode.value === 'instant') {
+    return 'icon-[lucide--fast-forward]'
+  }
+  if (queueMode.value === 'change') {
+    return 'icon-[lucide--step-forward]'
+  }
+  return 'icon-[lucide--play]'
+})
+
+const queueButtonTooltip = computed(() => {
+  if (hasMissingNodes.value) {
+    return t('menu.runWorkflowDisabled')
+  }
+  if (workspaceStore.shiftDown) {
+    return t('menu.runWorkflowFront')
+  }
+  return t('menu.runWorkflow')
+})
+
 const commandStore = useCommandStore()
 const queuePrompt = async (e: Event) => {
   const isShiftPressed = 'shiftKey' in e && e.shiftKey
diff --git a/src/components/breadcrumb/SubgraphBreadcrumbItem.vue b/src/components/breadcrumb/SubgraphBreadcrumbItem.vue
index a0c405971..2e8692558 100644
--- a/src/components/breadcrumb/SubgraphBreadcrumbItem.vue
+++ b/src/components/breadcrumb/SubgraphBreadcrumbItem.vue
@@ -2,7 +2,7 @@
   <a
     ref="wrapperRef"
     v-tooltip.bottom="{
-      value: item.label,
+      value: tooltipText,
       showDelay: 512
     }"
     draggable="false"
@@ -16,6 +16,10 @@
     }"
     @click="handleClick"
   >
+    <i
+      v-if="hasMissingNodes && isRoot"
+      class="icon-[lucide--triangle-alert] text-warning-background"
+    />
     <span class="p-breadcrumb-item-label px-2">{{ item.label }}</span>
     <Tag v-if="item.isBlueprint" :value="'Blueprint'" severity="primary" />
     <i v-if="isActive" class="pi pi-angle-down text-[10px]"></i>
@@ -64,6 +68,7 @@ import { useDialogService } from '@/services/dialogService'
 import { useCommandStore } from '@/stores/commandStore'
 import { useSubgraphNavigationStore } from '@/stores/subgraphNavigationStore'
 import { appendJsonExt } from '@/utils/formatUtil'
+import { useMissingNodes } from '@/workbench/extensions/manager/composables/nodePack/useMissingNodes'
 
 interface Props {
   item: MenuItem
@@ -74,6 +79,8 @@ const props = withDefaults(defineProps<Props>(), {
   isActive: false
 })
 
+const { hasMissingNodes } = useMissingNodes()
+
 const { t } = useI18n()
 const menu = ref<InstanceType<typeof Menu> & MenuState>()
 const dialogService = useDialogService()
@@ -115,6 +122,14 @@ const rename = async (
 }
 
 const isRoot = props.item.key === 'root'
+
+const tooltipText = computed(() => {
+  if (hasMissingNodes.value && isRoot) {
+    return t('breadcrumbsMenu.missingNodesWarning')
+  }
+  return props.item.label
+})
+
 const menuItems = computed<MenuItem[]>(() => {
   return [
     {
diff --git a/src/locales/en/main.json b/src/locales/en/main.json
index 1fbd12356..77a087b14 100644
--- a/src/locales/en/main.json
+++ b/src/locales/en/main.json
@@ -779,6 +779,7 @@
     "onChangeTooltip": "The workflow will be queued once a change is made",
     "runWorkflow": "Run workflow (Shift to queue at front)",
     "runWorkflowFront": "Run workflow (Queue at front)",
+    "runWorkflowDisabled": "Workflow contains unsupported nodes (highlighted red). Remove these to run the workflow.",
     "run": "Run",
     "execute": "Execute",
     "interrupt": "Cancel current run",
@@ -1916,7 +1917,8 @@
     "clearWorkflow": "Clear Workflow",
     "deleteWorkflow": "Delete Workflow",
     "deleteBlueprint": "Delete Blueprint",
-    "enterNewName": "Enter new name"
+    "enterNewName": "Enter new name",
+    "missingNodesWarning": "Workflow contains unsupported nodes (highlighted red)."
   },
   "shortcuts": {
     "shortcuts": "Shortcuts",
diff --git a/src/workbench/extensions/manager/composables/nodePack/useMissingNodes.ts b/src/workbench/extensions/manager/composables/nodePack/useMissingNodes.ts
index 3585d05c8..580a687fc 100644
--- a/src/workbench/extensions/manager/composables/nodePack/useMissingNodes.ts
+++ b/src/workbench/extensions/manager/composables/nodePack/useMissingNodes.ts
@@ -1,8 +1,10 @@
 import { groupBy } from 'es-toolkit/compat'
-import { computed, onMounted } from 'vue'
+import { createSharedComposable } from '@vueuse/core'
+import { computed, watch } from 'vue'
 
 import type { NodeProperty } from '@/lib/litegraph/src/LGraphNode'
 import type { LGraphNode } from '@/lib/litegraph/src/litegraph'
+import { useWorkflowStore } from '@/platform/workflow/management/stores/workflowStore'
 import { app } from '@/scripts/app'
 import { useNodeDefStore } from '@/stores/nodeDefStore'
 import type { components } from '@/types/comfyRegistryTypes'
@@ -14,10 +16,12 @@ import { useComfyManagerStore } from '@/workbench/extensions/manager/stores/comf
  * Composable to find missing NodePacks from workflow
  * Uses the same filtering approach as ManagerDialogContent.vue
  * Automatically fetches workflow pack data when initialized
+ * This is a shared singleton composable - all components use the same instance
  */
-export const useMissingNodes = () => {
+export const useMissingNodes = createSharedComposable(() => {
   const nodeDefStore = useNodeDefStore()
   const comfyManagerStore = useComfyManagerStore()
+  const workflowStore = useWorkflowStore()
   const { workflowPacks, isLoading, error, startFetchWorkflowPacks } =
     useWorkflowPacks()
 
@@ -61,17 +65,28 @@ export const useMissingNodes = () => {
     return groupBy(missingNodes, (node) => String(node.properties?.ver || ''))
   })
 
-  // Automatically fetch workflow pack data when composable is used
-  onMounted(async () => {
-    if (!workflowPacks.value.length && !isLoading.value) {
-      await startFetchWorkflowPacks()
-    }
+  // Check if workflow has any missing nodes
+  const hasMissingNodes = computed(() => {
+    return (
+      missingNodePacks.value.length > 0 ||
+      Object.keys(missingCoreNodes.value).length > 0
+    )
   })
 
+  // Re-fetch workflow packs when active workflow changes
+  watch(
+    () => workflowStore.activeWorkflow,
+    async () => {
+      await startFetchWorkflowPacks()
+    },
+    { immediate: true }
+  )
+
   return {
     missingNodePacks,
     missingCoreNodes,
+    hasMissingNodes,
     isLoading,
     error
   }
-}
+})
diff --git a/tests-ui/tests/composables/useMissingNodes.test.ts b/tests-ui/tests/composables/useMissingNodes.test.ts
index a04bb6041..9dbfa8a56 100644
--- a/tests-ui/tests/composables/useMissingNodes.test.ts
+++ b/tests-ui/tests/composables/useMissingNodes.test.ts
@@ -9,12 +9,12 @@ import { useMissingNodes } from '@/workbench/extensions/manager/composables/node
 import { useWorkflowPacks } from '@/workbench/extensions/manager/composables/nodePack/useWorkflowPacks'
 import { useComfyManagerStore } from '@/workbench/extensions/manager/stores/comfyManagerStore'
 
-// Mock Vue's onMounted to execute immediately for testing
-vi.mock('vue', async () => {
-  const actual = await vi.importActual<typeof import('vue')>('vue')
+vi.mock('@vueuse/core', async () => {
+  const actual =
+    await vi.importActual<typeof import('@vueuse/core')>('@vueuse/core')
   return {
     ...actual,
-    onMounted: (cb: () => void) => cb()
+    createSharedComposable: <Fn extends (...args: any[]) => any>(fn: Fn) => fn
   }
 })
 
@@ -34,6 +34,12 @@ vi.mock('@/stores/nodeDefStore', () => ({
   useNodeDefStore: vi.fn()
 }))
 
+vi.mock('@/platform/workflow/management/stores/workflowStore', () => ({
+  useWorkflowStore: vi.fn(() => ({
+    activeWorkflow: null
+  }))
+}))
+
 vi.mock('@/scripts/app', () => ({
   app: {
     graph: {
@@ -176,13 +182,13 @@ describe('useMissingNodes', () => {
   })
 
   describe('automatic data fetching', () => {
-    it('fetches workflow packs automatically when none exist', async () => {
+    it('fetches workflow packs automatically on initialization via watch with immediate:true', async () => {
       useMissingNodes()
 
       expect(mockStartFetchWorkflowPacks).toHaveBeenCalledOnce()
     })
 
-    it('does not fetch when packs already exist', async () => {
+    it('fetches even when packs already exist (watch always fires with immediate:true)', async () => {
       mockUseWorkflowPacks.mockReturnValue({
         workflowPacks: ref(mockWorkflowPacks),
         isLoading: ref(false),
@@ -194,10 +200,10 @@ describe('useMissingNodes', () => {
 
       useMissingNodes()
 
-      expect(mockStartFetchWorkflowPacks).not.toHaveBeenCalled()
+      expect(mockStartFetchWorkflowPacks).toHaveBeenCalledOnce()
     })
 
-    it('does not fetch when already loading', async () => {
+    it('fetches even when already loading (watch fires regardless of loading state)', async () => {
       mockUseWorkflowPacks.mockReturnValue({
         workflowPacks: ref([]),
         isLoading: ref(true),
@@ -209,7 +215,7 @@ describe('useMissingNodes', () => {
 
       useMissingNodes()
 
-      expect(mockStartFetchWorkflowPacks).not.toHaveBeenCalled()
+      expect(mockStartFetchWorkflowPacks).toHaveBeenCalledOnce()
     })
   })