diff --git a/apps/web/src/lib/router.tsx b/apps/web/src/lib/router.tsx
index 7f2778e..0969d1e 100644
--- a/apps/web/src/lib/router.tsx
+++ b/apps/web/src/lib/router.tsx
@@ -1,24 +1,67 @@
 import { createBrowserRouter, RouterProvider } from 'react-router';
-import { lazy, Suspense } from 'react';
+import { lazy, Suspense, type ComponentType } from 'react';
 import { AppShell } from '../components/layout/AppShell';
 import { SkeletonCard } from '../components/ui/SkeletonCard';
+import { Button } from '../components/ui/Button';
 
-const Dashboard = lazy(() => import('../routes/dashboard').then((m) => ({ default: m.DashboardRoute })));
-const Heute = lazy(() =>
-  import('../routes/heute').then((m) => ({ default: m.HeuteRoute })),
+// Nach einem Deploy zeigen bereits offene Tabs auf alte, inzwischen gelöschte
+// Chunk-Dateien (gehashte Dateinamen). Der nächste Lazy-Import schlägt dann fehl
+// („Failed to fetch dynamically imported module"). Ein einmaliger Reload holt die
+// frische index.html mit den neuen Hashes. sessionStorage-Guard verhindert eine
+// Reload-Schleife, falls der Fehler eine andere Ursache hat (z. B. offline).
+const RELOAD_KEY = 'ebw:chunk-reload';
+
+function reloadOnceForStaleChunk(): boolean {
+  const last = Number(sessionStorage.getItem(RELOAD_KEY) ?? '0');
+  if (Date.now() - last > 10_000) {
+    sessionStorage.setItem(RELOAD_KEY, String(Date.now()));
+    window.location.reload();
+    return true;
+  }
+  return false;
+}
+
+function lazyWithReload<T extends ComponentType>(factory: () => Promise<{ default: T }>) {
+  return lazy(() =>
+    factory().catch((err: unknown) => {
+      if (reloadOnceForStaleChunk()) {
+        // Hängt bis der Reload greift — vermeidet ein kurzes Aufblitzen des Fehlers.
+        return new Promise<{ default: T }>(() => {});
+      }
+      throw err;
+    }),
+  );
+}
+
+// Vite feuert dieses Event bei fehlgeschlagenem modulepreload (gleiche Ursache).
+if (typeof window !== 'undefined') {
+  window.addEventListener('vite:preloadError', (e) => {
+    if (reloadOnceForStaleChunk()) e.preventDefault();
+  });
+}
+
+const Dashboard = lazyWithReload(() =>
+  import('../routes/dashboard').then((m) => ({ default: m.DashboardRoute })),
 );
-const Reflexion = lazy(() =>
+const Heute = lazyWithReload(() => import('../routes/heute').then((m) => ({ default: m.HeuteRoute })));
+const Reflexion = lazyWithReload(() =>
   import('../routes/reflexion').then((m) => ({ default: m.ReflexionRoute })),
 );
-const Bereich = lazy(() => import('../routes/bereich').then((m) => ({ default: m.BereichRoute })));
-const Projekt = lazy(() => import('../routes/projekt').then((m) => ({ default: m.ProjektRoute })));
-const Leads = lazy(() => import('../routes/leads').then((m) => ({ default: m.LeadsRoute })));
-const Lead = lazy(() => import('../routes/lead').then((m) => ({ default: m.LeadRoute })));
-const Archiv = lazy(() => import('../routes/archiv').then((m) => ({ default: m.ArchivRoute })));
-const NotFound = lazy(() =>
+const Bereich = lazyWithReload(() =>
+  import('../routes/bereich').then((m) => ({ default: m.BereichRoute })),
+);
+const Projekt = lazyWithReload(() =>
+  import('../routes/projekt').then((m) => ({ default: m.ProjektRoute })),
+);
+const Leads = lazyWithReload(() => import('../routes/leads').then((m) => ({ default: m.LeadsRoute })));
+const Lead = lazyWithReload(() => import('../routes/lead').then((m) => ({ default: m.LeadRoute })));
+const Archiv = lazyWithReload(() =>
+  import('../routes/archiv').then((m) => ({ default: m.ArchivRoute })),
+);
+const NotFound = lazyWithReload(() =>
   import('../routes/not-found').then((m) => ({ default: m.NotFoundRoute })),
 );
-const Login = lazy(() => import('../routes/login').then((m) => ({ default: m.LoginRoute })));
+const Login = lazyWithReload(() => import('../routes/login').then((m) => ({ default: m.LoginRoute })));
 
 function withSuspense(node: React.ReactNode) {
   return (
@@ -26,14 +69,30 @@ function withSuspense(node: React.ReactNode) {
   );
 }
 
+function RouteError() {
+  return (
+    <div className="mx-auto mt-16 max-w-md text-center">
+      <h1 className="text-lg font-semibold">Etwas ist schiefgelaufen.</h1>
+      <p className="mt-1 text-sm text-[var(--color-ink-muted)]">
+        Wahrscheinlich wurde gerade eine neue Version veröffentlicht. Lade die Seite neu.
+      </p>
+      <Button className="mt-4" onClick={() => window.location.reload()}>
+        Neu laden
+      </Button>
+    </div>
+  );
+}
+
 const router = createBrowserRouter([
   {
     path: '/login',
     element: withSuspense(<Login />),
+    errorElement: <RouteError />,
   },
   {
     path: '/',
     element: <AppShell />,
+    errorElement: <RouteError />,
     children: [
       { index: true, element: withSuspense(<Dashboard />) },
       { path: 'dashboard', element: withSuspense(<Dashboard />) },