UIFreeze: Tried to remove a willPop callback from a route that is not currently in the tree.

[anburocky3]

I noticed that, after i call this:

context.showSuccessBar(content: Text('Authentication verified!'));

It is displaying properly on the UI, but on the log, i can see this trace. And during that, my UI is freezen, i have to restart my app to use my app. Why is that?

======== Exception caught by animation library =====================================================
The following assertion was thrown while notifying status listeners for AnimationController:
Tried to remove a willPop callback from a route that is not currently in the tree.
'package:flutter/src/widgets/routes.dart':
Failed assertion: line 1508 pos 12: '_scopeKey.currentState != null'

When the exception was thrown, this was the stack: 
#2      ModalRoute.removeScopedWillPopCallback (package:flutter/src/widgets/routes.dart:1508:12)
#3      FlashController.dismissInternal (package:flash/flash.dart:224:35)
#4      FlashController.dispose (package:flash/flash.dart:244:5)
#5      FlashController._handleStatusChanged (package:flash/flash.dart:159:9)
#6      AnimationLocalStatusListenersMixin.notifyStatusListeners (package:flutter/src/animation/listener_helpers.dart:233:19)
#7      AnimationController._checkStatusChanged (package:flutter/src/animation/animation_controller.dart:815:7)
#8      AnimationController._tick (package:flutter/src/animation/animation_controller.dart:831:5)
#9      Ticker._tick (package:flutter/src/scheduler/ticker.dart:238:12)
#10     SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1146:15)
#11     SchedulerBinding.handleBeginFrame.<anonymous closure> (package:flutter/src/scheduler/binding.dart:1059:11)
#12     _LinkedHashMapMixin.forEach (dart:collection-patch/compact_hash.dart:614:13)
#13     SchedulerBinding.handleBeginFrame (package:flutter/src/scheduler/binding.dart:1057:17)
#14     SchedulerBinding._handleBeginFrame (package:flutter/src/scheduler/binding.dart:976:5)
#18     _invoke1 (dart:ui/hooks.dart:170:10)
#19     PlatformDispatcher._beginFrame (dart:ui/platform_dispatcher.dart:286:5)
#20     _beginFrame (dart:ui/hooks.dart:104:31)
(elided 5 frames from class _AssertionError and dart:async)
The AnimationController notifying status listeners was: AnimationController#a3606(⏮ 0.000; paused; for FlashController<dynamic>)

[sososdk]

@anburocky3 I can't reproduce it. Can you show your code and environment or provide an example?

[anburocky3]

Sorry, i have it in my project, is there any way, i can contact you via discord, to share the credentials?

[dzakybrori]

Sorry, i have it in my project, is there any way, i can contact you via discord, to share the credentials?

I'm facing the same issue either. In my case, it's because I called a Navigator Pop. so the BuildContext are not in the Stack anymore. So I tricked it with Future.delayed before navigator pop called.

[alextarana]

Facing the same issue.

[dzakybrori]

Facing the same issue.

You can try my solution above. It's not elegant solution, because delayed pretty much expensive task, but it works. I think the problem is, there is a async delay beetwen disposing Flash dan the Navigator.pop that makes current BuildContext already disposed and throw this error.

[dafinoer]

you need create the another completer for handle race condition.

var completer = Completer();
var completerFinishDialog = Completer();

context.showSuccessBar(content: Text('Authentication verified!')).then((_) => completerFinishDialog.complate());

completer.complate();
await completer.future;
await completerFinishDialog .future;

/// Navigator.pop() or replace