Null Exception when disconnecting from the device.

[01xJoao]

I get the following null exception when disconnecting:

1º

2º

StackTrace

stackTrace:#0      Object.noSuchMethod (dart:core-patch/object_patch.dart:53:5)
#1      PluginScaffold._setChannelCallHandler.<anonymous closure> (package:plugin_scaffold/plugin_scaffold.dart:24:27)
#2      MethodChannel._handleAsMethodCall (package:flutter/src/services/platform_channel.dart:409:55)
#3      MethodChannel.setMethodCallHandler.<anonymous closure> (package:flutter/src/services/platform_channel.dart:377:54)
#4      _DefaultBinaryMessenger.handlePlatformMessage (package:flutter/src/services/binding.dart:263:33)
#5      _invoke3.<anonymous closure> (dart:ui/hooks.dart:290:15)
#6      _rootRun (dart:async/zone.dart:1184:13)
#7      _CustomZone.run (dart:async/zone.dart:1077:19)
#8      _CustomZone.runGuarded (dart:async/zone.dart:979:7)
#9      _invoke3 (dart:ui/hooks.dart:289:10)
#10     _dispatchPlatformMessage (dart:ui/hooks.dart:164:5)