Unhandled Exception: Null check operator used on a null value

[zzzaJ]

When trying to show a FlushbarHelper.createSuccess() flusher, it fails with the following error and trace stack:

Unhandled Exception: Null check operator used on a null value
#0 StatefulElement.state
package:flutter/…/widgets/framework.dart:4789
#1 Navigator.of
package:flutter/…/widgets/navigator.dart:2730
#2 Flushbar.show
package:another_flushbar/flushbar.dart:233
#3 _LoginState.build.
package:app/…/auth/login.dart:258

I am not sure why this is the case, and any help or advice would be great.

[kcchenkd]

Observing the same error on 1.10.28 version

I/flutter ( 4761): ----------------FIREBASE CRASHLYTICS----------------
I/flutter ( 4761): Null check operator used on a null value
I/flutter ( 4761):
I/flutter ( 4761): #0 StatefulElement.state
package:flutter/…/widgets/framework.dart:4712
I/flutter ( 4761): #1 Navigator.of
package:flutter/…/widgets/navigator.dart:2542
I/flutter ( 4761): #2 Flushbar.show
package:another_flushbar/flushbar.dart:233
I/flutter ( 4761): #3 _HomePageState._showFlushBar
package:groubing/…/pages/home_page.dart:358
I/flutter ( 4761): #4 _HomePageState._configureFcm.
package:groubing/…/pages/home_page.dart:301
I/flutter ( 4761): #5 _rootRunUnary (dart:async/zone.dart:1436:47)
I/flutter ( 4761): #6 _CustomZone.runUnary (dart:async/zone.dart:1335:19)
I/flutter ( 4761): #7 _CustomZone.runUnaryGuarded (dart:async/zone.dart:1244:7)
I/flutter ( 4761): #8 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:341:11)
I/flutter ( 4761): #9 _DelayedData.perform (dart:async/stream_impl.dart:591:14)
I/flutter ( 4761): #10 _StreamImplEvents.handleNext (dart:async/stream_impl.dart:706:11)
I/flutter ( 4761): #11 _PendingEvents.schedule. (dart:async/stream_impl.dart:663:7)
I/flutter ( 4761): #12 _rootRun (dart:async/zone.dart:1420:47)
I/flutter ( 4761): #13 _CustomZone.run (dart:async/zone.dart:1328:19)
I/flutter ( 4761): #14 _
I/flutter ( 4761): ----------------------------------------------------

[bagus-repository]

I do have same issue

[cyb9701]

The reason for this error is that the Flushbar result value is null.
Therefore, if the bool enables null, no error occurs.

Flushbar<bool?>? _flushBar;

_flushBar = Flushbar<bool?>()