#sample project showing my error
output:
Performing hot restart...
Restarted app in 2,516ms.
E/flutter (31481): [ERROR:topaz/lib/tonic/logging/dart_error.cc(16)] Unhandled exception:
E/flutter (31481): Looking up a deactivated widget's ancestor is unsafe.
E/flutter (31481): At this point the state of the widget's element tree is no longer stable. To safely refer to a widget's ancestor in its dispose() method, save a reference to the ancestor by calling inheritFromWidgetOfExactType() in the widget's didChangeDependencies() method.
E/flutter (31481):
E/flutter (31481): #0 Element._debugCheckStateIsActiveForAncestorLookup.<anonymous closure> (package:flutter/src/widgets/framework.dart:3203:9)
E/flutter (31481): #1 Element._debugCheckStateIsActiveForAncestorLookup (package:flutter/src/widgets/framework.dart:3212:6)
E/flutter (31481): #2 Element.ancestorStateOfType (package:flutter/src/widgets/framework.dart:3254:12)
E/flutter (31481): #3 Navigator.of (package:flutter/src/widgets/navigator.dart:1176:19)
E/flutter (31481): #4 SecondScreen.build.<anonymous closure>.<anonymous closure>.<anonymous closure> (package:alert_bug/second_screen.dart:22:27)
E/flutter (31481): <asynchronous suspension>
E/flutter (31481): #5 _RootZone.runUnaryGuarded (dart:async/zone.dart:1316:10)
E/flutter (31481): #6 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:330:11)
E/flutter (31481): #7 _BufferingStreamSubscription._add (dart:async/stream_impl.dart:257:7)
E/flutter (31481): #8 _SyncBroadcastStreamController._sendData.<anonymous closure> (dart:async/broadcast_stream_controller.dart:387:20)
E/flutter (31481): #9 _BroadcastStreamController._forEachListener (dart:async/broadcast_stream_controller.dart:328:15)
E/flutter (31481): #10 _SyncBroadcastStreamController._sendData (dart:async/broadcast_stream_controller.dart:386:5)
E/flutter (31481): #11 _BroadcastStreamController.add (dart:async/broadcast_stream_controller.dart:254:5)
E/flutter (31481): #12 _AsBroadcastStreamController.add (dart:async/broadcast_stream_controller.dart:480:11)
E/flutter (31481): #13 _RootZone.runUnaryGuarded (dart:async/zone.dart:1316:10)
E/flutter (31481): #14 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:330:11)
E/flutter (31481): #15 _BufferingStreamSubscription._add (dart:async/stream_impl.dart:257:7)
E/flutter (31481): #16 _SyncBroadcastStreamController._sendData (dart:async/broadcast_stream_controller.dart:379:20)
E/flutter (31481): #17 _BroadcastStreamController.add (dart:async/broadcast_stream_controller.dart:254:5)
E/flutter (31481): #18 Stream.asyncMap.onListen.<anonymous closure> (dart:async/stream.dart:443:22)
E/flutter (31481): #19 _RootZone.runUnaryGuarded (dart:async/zone.dart:1316:10)
E/flutter (31481): #20 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:330:11)
E/flutter (31481): #21 _DelayedData.perform (dart:async/stream_impl.dart:578:14)
E/flutter (31481): #22 _StreamImplEvents.handleNext (dart:async/stream_impl.dart:694:11)
E/flutter (31481): #23 _PendingEvents.schedule.<anonymous closure> (dart:async/stream_impl.dart:654:7)
E/flutter (31481): #24 _microtaskLoop (dart:async/schedule_microtask.dart:41:21)
E/flutter (31481): #25 _startMicrotaskLoop (dart:async/schedule_microtask.dart:50:5)