Got this error in my App, and checking "mounted" fixed it:
NoSuchMethodError: NoSuchMethodError: The method 'markNeedsBuild' was called on null.
Receiver: null
Tried calling: markNeedsBuild()
File "framework.dart", line 1253, in State.setState
File "flutter_reorderable_list.dart", line 604, in _ReorderableItemState.update
File "flutter_reorderable_list.dart", line 402, in _ReorderableListState.end
File "<asynchronous suspension>"
File "unparsed"
https://api.flutter.dev/flutter/widgets/State/mounted.html
Got this error in my App, and checking "mounted" fixed it: