...

lib/pages/layout_detail.dart

@@ -55,8 +55,17 @@ class _LayoutDetailPageState extends State<LayoutDetailPage> {
 
   Future<void> _refreshLayout() async {
     final updated = await apiService.getStoreLayoutById(_layout.id);
-    if (updated != null && mounted) {
+    if (!mounted) return;
+    if (updated != null) {
       setState(() => _layout = updated);
+      return;
+    }
+
+    ScaffoldMessenger.of(context).showSnackBar(
+      const SnackBar(content: Text('Dieses Layout ist nicht mehr verfügbar.')),
+    );
+    if (mounted) {
+      Navigator.of(context).pop();
     }
   }
 

lib/pages/list_detail.dart

@@ -627,12 +627,11 @@ class _ListDetailPageState extends State<ListDetailPage> {
         ).showSnackBar(SnackBar(content: Text('"${item.name}" gelöscht.')));
       }
     } catch (e) {
+      if (!mounted) return;
       setState(() => _items.insert(index, item));
-      if (mounted) {
-        ScaffoldMessenger.of(
-          context,
-        ).showSnackBar(SnackBar(content: Text('Fehler beim Löschen: $e')));
-      }
+      ScaffoldMessenger.of(
+        context,
+      ).showSnackBar(SnackBar(content: Text('Fehler beim Löschen: $e')));
     }
   }
 
@@ -642,12 +641,11 @@ class _ListDetailPageState extends State<ListDetailPage> {
     try {
       await apiService.updateItem(item.id, checked: item.checked);
     } catch (e) {
+      if (!mounted) return;
       setState(() => item.checked = oldState);
-      if (mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
-          SnackBar(content: Text('Fehler beim Aktualisieren: $e')),
-        );
-      }
+      ScaffoldMessenger.of(context).showSnackBar(
+        SnackBar(content: Text('Fehler beim Aktualisieren: $e')),
+      );
     }
   }
 

lib/pages/login.dart

@@ -30,7 +30,9 @@ class _LoginPageState extends State<LoginPage> {
         await apiService.login(email, password);
       }
     } catch (e) {
-      setState(() => _error = e.toString());
+      if (mounted) {
+        setState(() => _error = e.toString());
+      }
     } finally {
       if (mounted) {
         setState(() => _loading = false);
@@ -38,6 +40,13 @@ class _LoginPageState extends State<LoginPage> {
     }
   }
 
+  @override
+  void dispose() {
+    _emailCtl.dispose();
+    _pwCtl.dispose();
+    super.dispose();
+  }
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(

lib/widgets/members_dialog.dart

@@ -80,16 +80,22 @@ class _MembersDialogState extends State<MembersDialog> {
       final List<String> newMembers = [...widget.list.members, user.id];
       await apiService.updateList(widget.list.id, members: newMembers);
 
-      setState(() {
-        widget.list.members = newMembers;
-        _userEmails[user.id] = user.data['email'] as String;
-        _emailCtl.clear();
-        _hasChanges = true;
-      });
+      if (mounted) {
+        setState(() {
+          widget.list.members = newMembers;
+          _userEmails[user.id] = user.data['email'] as String;
+          _emailCtl.clear();
+          _hasChanges = true;
+        });
+      }
     } catch (e) {
-      setState(() => _error = e.toString());
+      if (mounted) {
+        setState(() => _error = e.toString());
+      }
     } finally {
-      setState(() => _isLoading = false);
+      if (mounted) {
+        setState(() => _isLoading = false);
+      }
     }
   }
 
@@ -128,17 +134,29 @@ class _MembersDialogState extends State<MembersDialog> {
           .toList();
       await apiService.updateList(widget.list.id, members: newMembers);
 
-      setState(() {
-        widget.list.members = newMembers;
-        _hasChanges = true;
-      });
+      if (mounted) {
+        setState(() {
+          widget.list.members = newMembers;
+          _hasChanges = true;
+        });
+      }
     } catch (e) {
-      setState(() => _error = e.toString());
+      if (mounted) {
+        setState(() => _error = e.toString());
+      }
     } finally {
-      setState(() => _isLoading = false);
+      if (mounted) {
+        setState(() => _isLoading = false);
+      }
     }
   }
 
+  @override
+  void dispose() {
+    _emailCtl.dispose();
+    super.dispose();
+  }
+
   @override
   Widget build(BuildContext context) {
     final bool isOwner = widget.list.owner == apiService.userId;