Fehlerkorrekturen und Erweiterungen

lib/content_views/approach_area_page.dart

@@ -42,12 +42,22 @@ class _ApproachAreaPageState extends State<ApproachAreaPage> with ProducerMixin,
 
       _initCompleted = true;
 
-      setState(() {});
+      if (mounted) {
+        setState(() {});
+      }
     });
 
     _initMessages();
   }
 
+  @override
+  void dispose() {
+    // Unsubscribe from all message topics
+    unsubscribe(queueId: Constants.messageTopicRankingUpdated);
+
+    super.dispose();
+  }
+
   @override
   Widget build(BuildContext context) {
     if (!_initCompleted) {
@@ -204,7 +214,9 @@ class _ApproachAreaPageState extends State<ApproachAreaPage> with ProducerMixin,
       callback: (message) async {
         _ranking = await MyApp.isarInstance.rankings.where().findFirst();
 
-        setState(() {});
+        if (mounted) {
+          setState(() {});
+        }
       },
     );
   }