diff --git a/components/calendar/calendar-app.tsx b/components/calendar/calendar-app.tsx
index 01df6c83b..9c7ad076a 100644
--- a/components/calendar/calendar-app.tsx
+++ b/components/calendar/calendar-app.tsx
@@ -1981,7 +1981,30 @@ export function CalendarApp({ linkSegments: routeSegments }: CalendarAppProps =
               onCreateEvent={() => openCreateModal()}
             />
           );
-        case "tasks":
+        case "tasks": {
+          const taskList = (
+            <TaskListView
+              tasks={taskStore.tasks}
+              calendars={displayCalendars}
+              selectedCalendarIds={selectedCalendarIds}
+              filter={taskStore.filter}
+              onSelectTask={openEditTaskModal}
+              onToggleComplete={handleToggleTaskComplete}
+              selectedTaskId={taskStore.selectedTaskId}
+              onQuickCreate={(title) => {
+                // Into a calendar that takes it: the default one, else the
+                // first the user may write to.
+                const target = writableTaskCalendars.find((c) => c.isDefault) ?? writableTaskCalendars[0];
+                if (!client || !target) {
+                  toast.error(t("notifications.task_save_error"));
+                  return;
+                }
+                taskStore.createTask(client, { "@type": "Task", title, progress: "needs-action", calendarIds: { [target.id]: true } })
+                  .then((created) => { if (created) toast.success(t("notifications.task_created")); })
+                  .catch((error: unknown) => toast.error(describeError(error, t("notifications.task_save_error"))));
+              }}
+            />
+          );
           return (
             <div className="flex flex-col h-full">
               {taskStore.error === TASKS_LOAD_ERROR && (
@@ -1995,39 +2018,20 @@ export function CalendarApp({ linkSegments: routeSegments }: CalendarAppProps =
                 compact={isMobile}
               />
               {/* A plugin may draw the list itself (the calendar-task-view
-                  slot); the toolbar above stays Bulwark's. */}
+                  slot), with Bulwark's list back while its frame is not
+                  drawn; the toolbar above stays Bulwark's. */}
               {pluginTaskView ? (
                 <PluginTaskView
                   pluginId={pluginTaskView.pluginId}
                   fill={pluginTaskView.fill}
                   filter={taskStore.filter}
                   calendarIds={selectedCalendarIds}
+                  fallback={taskList}
                 />
-              ) : (
-                <TaskListView
-                  tasks={taskStore.tasks}
-                  calendars={displayCalendars}
-                  selectedCalendarIds={selectedCalendarIds}
-                  filter={taskStore.filter}
-                  onSelectTask={openEditTaskModal}
-                  onToggleComplete={handleToggleTaskComplete}
-                  selectedTaskId={taskStore.selectedTaskId}
-                  onQuickCreate={(title) => {
-                    // Into a calendar that takes it: the default one, else the
-                    // first the user may write to.
-                    const target = writableTaskCalendars.find((c) => c.isDefault) ?? writableTaskCalendars[0];
-                    if (!client || !target) {
-                      toast.error(t("notifications.task_save_error"));
-                      return;
-                    }
-                    taskStore.createTask(client, { "@type": "Task", title, progress: "needs-action", calendarIds: { [target.id]: true } })
-                      .then((created) => { if (created) toast.success(t("notifications.task_created")); })
-                      .catch((error: unknown) => toast.error(describeError(error, t("notifications.task_save_error"))));
-                  }}
-                />
-              )}
+              ) : taskList}
             </div>
           );
+        }
       }
     })();
 
diff --git a/components/plugins/__tests__/plugin-task-view.test.tsx b/components/plugins/__tests__/plugin-task-view.test.tsx
index 69e59a383..fc5988e2f 100644
--- a/components/plugins/__tests__/plugin-task-view.test.tsx
+++ b/components/plugins/__tests__/plugin-task-view.test.tsx
@@ -2,7 +2,8 @@ import { cleanup, render, waitFor } from '@testing-library/react';
 import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
 import type { InstalledPlugin } from '@/lib/plugin-types';
 
-const createSlotInstance = vi.fn((..._args: unknown[]) => ({ destroy: vi.fn(), updateProps: vi.fn(), setTheme: vi.fn() }));
+const slotInstance = (initPromise: Promise<unknown> = Promise.resolve({})) => ({ destroy: vi.fn(), updateProps: vi.fn(), setTheme: vi.fn(), initPromise });
+const createSlotInstance = vi.fn((..._args: unknown[]) => slotInstance());
 vi.mock('@/lib/plugin-sandbox/host-bridge', () => ({
   createSlotInstance: (...args: unknown[]) => createSlotInstance(...args),
 }));
@@ -11,7 +12,7 @@ vi.mock('@/lib/plugin-sandbox/host-theme', () => ({ snapshotHostTheme: () => ({}
 const { PluginTaskView, usePluginTaskView } = await import('../plugin-task-view');
 const registry = await import('@/lib/plugin-sandbox/registry');
 
-function offer(id: string, opts: { slot?: string; fill?: boolean; permissions?: InstalledPlugin['permissions'] } = {}) {
+function offer(id: string, opts: { slot?: string; fill?: boolean; permissions?: InstalledPlugin['permissions']; shouldShow?: boolean } = {}) {
   const permissions = opts.permissions ?? ['ui:tasks', 'tasks:read'];
   const plugin: InstalledPlugin = {
     id, name: id, version: '1.0.0', author: '', description: '', type: 'ui-extension',
@@ -22,8 +23,8 @@ function offer(id: string, opts: { slot?: string; fill?: boolean; permissions?:
     plugin,
     code: '',
     tier: 'untrusted',
-    background: { evaluateShouldShow: vi.fn(async () => true) } as never,
-    slotOffers: [{ name: (opts.slot ?? 'calendar-task-view') as never, order: 100, hasShouldShow: false, ...(opts.fill ? { fill: true } : {}) }],
+    background: { evaluateShouldShow: vi.fn(async () => opts.shouldShow ?? true) } as never,
+    slotOffers: [{ name: (opts.slot ?? 'calendar-task-view') as never, order: 100, hasShouldShow: opts.shouldShow !== undefined, ...(opts.fill ? { fill: true } : {}) }],
     hookDisposables: [],
   });
 }
@@ -31,8 +32,9 @@ function offer(id: string, opts: { slot?: string; fill?: boolean; permissions?:
 /** The task view's list area as calendar-app draws it. */
 function TaskArea({ calendarIds = ['c1', 'c2'] }: { calendarIds?: string[] }) {
   const view = usePluginTaskView();
-  if (!view) return <div data-testid="bulwark-task-list" />;
-  return <PluginTaskView pluginId={view.pluginId} fill={view.fill} filter="pending" calendarIds={calendarIds} />;
+  const list = <div data-testid="bulwark-task-list" />;
+  if (!view) return list;
+  return <PluginTaskView pluginId={view.pluginId} fill={view.fill} filter="pending" calendarIds={calendarIds} fallback={list} />;
 }
 
 beforeEach(() => { createSlotInstance.mockClear(); });
@@ -64,6 +66,8 @@ describe('calendar-task-view', () => {
     expect(opts.fill).toBe(true);
     expect(opts.extraProps).toEqual({ filter: 'pending', calendarIds: ['c1', 'c2'] });
     expect(container.querySelector('[data-plugin-iframe-fill]')).not.toBeNull();
+    await Promise.resolve();
+    expect(queryByTestId('bulwark-task-list')).toBeNull();
   });
 
   it('hands the calendars only to a plugin that reads tasks', async () => {
@@ -74,6 +78,23 @@ describe('calendar-task-view', () => {
     expect(opts.extraProps).toEqual({ filter: 'pending' });
   });
 
+  it("gives Bulwark's list back when the plugin's shouldShow says no", async () => {
+    offer('picky', { shouldShow: false });
+    const { findByTestId, container } = render(<TaskArea />);
+    expect(await findByTestId('bulwark-task-list')).toBeInTheDocument();
+    expect(createSlotInstance).not.toHaveBeenCalled();
+    expect(container.querySelector('[data-plugin-task-view]')).toHaveClass('hidden');
+  });
+
+  it("gives Bulwark's list back when the plugin's frame fails to start", async () => {
+    createSlotInstance.mockImplementationOnce(() => slotInstance(Promise.reject(new Error('boom'))));
+    offer('broken');
+    const { findByTestId, container } = render(<TaskArea />);
+    expect(await findByTestId('bulwark-task-list')).toBeInTheDocument();
+    expect(createSlotInstance).toHaveBeenCalledTimes(1);
+    expect(container.querySelector('[data-plugin-task-view]')).toHaveClass('hidden');
+  });
+
   it('lets the area scroll for a plugin that does not fill it', async () => {
     offer('plain');
     const { container } = render(<TaskArea />);
diff --git a/components/plugins/plugin-iframe-slot.tsx b/components/plugins/plugin-iframe-slot.tsx
index e02b9bcc9..1865ce624 100644
--- a/components/plugins/plugin-iframe-slot.tsx
+++ b/components/plugins/plugin-iframe-slot.tsx
@@ -25,6 +25,13 @@ interface Props {
   extraProps?: Record<string, unknown>;
   /** The frame fills its panel and scrolls inside, instead of growing with its content. */
   fill?: boolean;
+  /**
+   * Told whether the frame is up: false when the plugin's shouldShow says no
+   * or its frame fails to start, true once it has started. For a slot that
+   * stands in for a part of Bulwark (calendar-task-view), so the caller can
+   * draw its own part again.
+   */
+  onShownChange?: (shown: boolean) => void;
 }
 
 interface FloatingDropdownState {
@@ -38,9 +45,11 @@ interface FloatingDropdownState {
   ariaLabel?: string;
 }
 
-export function PluginIframeSlot({ pluginId, slot, extraProps, fill = false }: Props) {
+export function PluginIframeSlot({ pluginId, slot, extraProps, fill = false, onShownChange }: Props) {
   const wrapperRef = useRef<HTMLDivElement>(null);
   const instanceRef = useRef<SandboxInstance | null>(null);
+  const onShownChangeRef = useRef(onShownChange);
+  useEffect(() => { onShownChangeRef.current = onShownChange; }, [onShownChange]);
   const [height, setHeight] = useState<number>(0);
   const [width, setWidth] = useState<number | undefined>(undefined);
   const [floatingDropdown, setFloatingDropdown] = useState<FloatingDropdownState | null>(null);
@@ -80,6 +89,10 @@ export function PluginIframeSlot({ pluginId, slot, extraProps, fill = false }: P
     return () => { cancelled = true; };
   }, [pluginId, slot, props]);
 
+  useEffect(() => {
+    if (show === false) onShownChangeRef.current?.(false);
+  }, [show]);
+
   // Spawn / tear down the slot iframe.
   useEffect(() => {
     if (show !== true) return;
@@ -130,7 +143,17 @@ export function PluginIframeSlot({ pluginId, slot, extraProps, fill = false }: P
       },
     });
     instanceRef.current = inst;
+    // A frame that fails to start stays blank; say so to a caller that can
+    // draw something in its place.
+    let live = true;
+    if (onShownChangeRef.current) {
+      inst.initPromise.then(
+        () => { if (live) onShownChangeRef.current?.(true); },
+        () => { if (live) onShownChangeRef.current?.(false); },
+      );
+    }
     return () => {
+      live = false;
       try { inst.destroy(); } catch { /* ignore */ }
       instanceRef.current = null;
       setFloatingDropdown(null);
diff --git a/components/plugins/plugin-task-view.tsx b/components/plugins/plugin-task-view.tsx
index 7684ac3a3..eb5fdd6bd 100644
--- a/components/plugins/plugin-task-view.tsx
+++ b/components/plugins/plugin-task-view.tsx
@@ -1,6 +1,6 @@
 'use client';
 
-import { useMemo } from 'react';
+import { useCallback, useMemo, useState, type ReactNode } from 'react';
 import { usePluginSlotOffers } from '@/hooks/use-plugin-slot-offers';
 import type { TaskViewFilter } from '@/stores/task-store';
 import { cn } from '@/lib/utils';
@@ -9,7 +9,8 @@ import { PluginIframeSlot } from './plugin-iframe-slot';
 // The `calendar-task-view` slot: a plugin drawing the calendar's task view
 // below its toolbar, in place of Bulwark's task list. One plugin at a time,
 // the first offering it (by its offer's order, then the plugins' order);
-// none, and the calendar shows its own list.
+// none, and the calendar shows its own list. So does a plugin whose
+// shouldShow says no or whose frame fails to start.
 
 /** The plugin drawing the task view, or null when none offers it. */
 export function usePluginTaskView(): { pluginId: string; fill: boolean } | null {
@@ -21,25 +22,35 @@ export function usePluginTaskView(): { pluginId: string; fill: boolean } | null
 /**
  * The plugin's frame in the area below the task toolbar: filled when the
  * plugin asks for it (it scrolls inside), else the area scrolls. Its props:
- * the toolbar's filter and the calendars ticked in the sidebar.
+ * the toolbar's filter and the calendars ticked in the sidebar. `fallback`
+ * (Bulwark's list) stands in while the frame is not drawn.
  */
-export function PluginTaskView({ pluginId, fill, filter, calendarIds }: {
+export function PluginTaskView({ pluginId, fill, filter, calendarIds, fallback }: {
   pluginId: string;
   fill: boolean;
   filter: TaskViewFilter;
   calendarIds: readonly string[];
+  fallback: ReactNode;
 }) {
   // One array per set of ids, so the frame gets no update while they stay.
   const idsKey = calendarIds.join('\u0000');
   const ids = useMemo(() => (idsKey ? idsKey.split('\u0000') : []), [idsKey]);
   const extraProps = useMemo(() => ({ filter, calendarIds: ids }), [filter, ids]);
+  // The plugin whose frame is not drawn. The frame stays mounted (hidden),
+  // so a shouldShow that says yes for another filter takes the view back.
+  const [notShownBy, setNotShownBy] = useState<string | null>(null);
+  const notShown = notShownBy === pluginId;
+  const onShownChange = useCallback((shown: boolean) => setNotShownBy(shown ? null : pluginId), [pluginId]);
   return (
-    <div
-      data-plugin-slot="calendar-task-view"
-      data-plugin-task-view={pluginId}
-      className={cn('min-h-0 flex-1', fill ? 'flex flex-col' : 'overflow-y-auto')}
-    >
-      <PluginIframeSlot key={pluginId} pluginId={pluginId} slot="calendar-task-view" extraProps={extraProps} fill={fill} />
-    </div>
+    <>
+      {notShown && fallback}
+      <div
+        data-plugin-slot="calendar-task-view"
+        data-plugin-task-view={pluginId}
+        className={cn('min-h-0 flex-1', fill ? 'flex flex-col' : 'overflow-y-auto', notShown && 'hidden')}
+      >
+        <PluginIframeSlot key={pluginId} pluginId={pluginId} slot="calendar-task-view" extraProps={extraProps} fill={fill} onShownChange={onShownChange} />
+      </div>
+    </>
   );
 }