diff --git a/backend/routers/caldav_router.py b/backend/routers/caldav_router.py
index a0d61aa..1aa38e4 100644
--- a/backend/routers/caldav_router.py
+++ b/backend/routers/caldav_router.py
@@ -347,13 +347,15 @@ def get_events(
         .filter(models.GoogleAccount.user_id == current_user.id)
         .all()
     )
+    google_errors = []
     for g_acc in google_accounts:
         try:
             all_events.extend(get_google_events(g_acc, start_dt, end_dt, db))
         except Exception as exc:
             logger.error("Error fetching Google Calendar for %s: %s", g_acc.email, exc)
+            google_errors.append({"email": g_acc.email})
 
-    return all_events
+    return {"events": all_events, "errors": google_errors}
 
 
 @router.post("/events")
diff --git a/backend/routers/google_router.py b/backend/routers/google_router.py
index d771d61..0a1c443 100644
--- a/backend/routers/google_router.py
+++ b/backend/routers/google_router.py
@@ -373,8 +373,9 @@ def get_google_events(account: models.GoogleAccount, start_dt: datetime, end_dt:
     """Fetch events from all enabled Google calendars for an account."""
     try:
         token = _refresh_access_token(account, db)
-    except Exception:
-        return []
+    except Exception as exc:
+        logger.error("Token refresh failed for Google account %s: %s", account.email, exc)
+        raise
 
     all_events = []
     try:
diff --git a/frontend/js/calendar.js b/frontend/js/calendar.js
index bfa22a3..631d012 100644
--- a/frontend/js/calendar.js
+++ b/frontend/js/calendar.js
@@ -124,7 +124,7 @@ function prefetchIfNeeded(viewStart, viewEnd) {
     const from = new Date(eventCache.end);
     const to   = new Date(eventCache.end.getTime() + PREFETCH_EXT);
     api.get(`/caldav/events?start=${from.toISOString()}&end=${to.toISOString()}`)
-      .then(evs => { _mergeEvents(evs); eventCache.end = to; })
+      .then(r => { _mergeEvents(r.events || r); eventCache.end = to; })
       .catch(() => {})
       .finally(() => { eventCache._fwdPending = false; });
   }
@@ -134,7 +134,7 @@ function prefetchIfNeeded(viewStart, viewEnd) {
     const from = new Date(eventCache.start.getTime() - PREFETCH_EXT);
     const to   = new Date(eventCache.start);
     api.get(`/caldav/events?start=${from.toISOString()}&end=${to.toISOString()}`)
-      .then(evs => { _mergeEvents(evs); eventCache.start = from; })
+      .then(r => { _mergeEvents(r.events || r); eventCache.start = from; })
       .catch(() => {})
       .finally(() => { eventCache._bwdPending = false; });
   }
@@ -161,7 +161,13 @@ async function fetchAndRender(force = false) {
 
   showLoading();
   try {
-    const events = await api.get(`/caldav/events?start=${fetchStart.toISOString()}&end=${fetchEnd.toISOString()}`);
+    const resp = await api.get(`/caldav/events?start=${fetchStart.toISOString()}&end=${fetchEnd.toISOString()}`);
+    const events = resp.events || resp;
+    if (resp.errors && resp.errors.length) {
+      for (const err of resp.errors) {
+        showToast(`Google (${err.email}): Token abgelaufen – bitte Konto trennen und neu verbinden`, true);
+      }
+    }
     eventCache.start  = fetchStart;
     eventCache.end    = fetchEnd;
     eventCache.events = events;