diff --git a/devtools_options.yaml b/devtools_options.yaml
new file mode 100644
index 0000000..fa0b357
--- /dev/null
+++ b/devtools_options.yaml
@@ -0,0 +1,3 @@
+description: This file stores settings for Dart & Flutter DevTools.
+documentation: https://docs.flutter.dev/tools/devtools/extensions#configure-extension-enablement-states
+extensions:
diff --git a/lib/pages/layout_detail.dart b/lib/pages/layout_detail.dart
index b17ad35..944daaf 100644
--- a/lib/pages/layout_detail.dart
+++ b/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();
     }
   }
 
diff --git a/lib/pages/list_detail.dart b/lib/pages/list_detail.dart
index b6b37bf..383220c 100644
--- a/lib/pages/list_detail.dart
+++ b/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')),
+      );
     }
   }
 
diff --git a/lib/pages/login.dart b/lib/pages/login.dart
index 784b072..f913356 100644
--- a/lib/pages/login.dart
+++ b/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(
diff --git a/lib/widgets/members_dialog.dart b/lib/widgets/members_dialog.dart
index 49fc3d9..2336855 100644
--- a/lib/widgets/members_dialog.dart
+++ b/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;
diff --git a/pubspec.lock b/pubspec.lock
index d4dbce6..2fd4d7b 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -172,10 +172,10 @@ packages:
     dependency: transitive
     description:
       name: meta
-      sha256: e3641ec5d63ebf0d9b41bd43201a66e3fc79a65db5f61fc181f04cd27aab950c
+      sha256: "23f08335362185a5ea2ad3a4e597f1375e78bce8a040df5c600c8d3552ef2394"
       url: "https://pub.dev"
     source: hosted
-    version: "1.16.0"
+    version: "1.17.0"
   nested:
     dependency: transitive
     description:
@@ -393,10 +393,10 @@ packages:
     dependency: transitive
     description:
       name: test_api
-      sha256: "522f00f556e73044315fa4585ec3270f1808a4b186c936e612cab0b565ff1e00"
+      sha256: ab2726c1a94d3176a45960b6234466ec367179b87dd74f1611adb1f3b5fb9d55
       url: "https://pub.dev"
     source: hosted
-    version: "0.7.6"
+    version: "0.7.7"
   typed_data:
     dependency: transitive
     description: