CRASH: Null check operator used on a null value

[dhirajhimani]

Logs:-

ReorderableListener._startDragging (flutter_reorderable_list.dart:147)
ReorderableListener._routePointer (flutter_reorderable_list.dart:125)
ReorderableListener.build. (flutter_reorderable_list.dart:118)
RenderPointerListener.handleEvent (proxy_box.dart:2829)
GestureBinding.dispatchEvent (binding.dart:419)
RendererBinding.dispatchEvent (binding.dart:287)
GestureBinding._handlePointerEventImmediately (binding.dart:374)
GestureBinding.handlePointerEvent (binding.dart:338)
GestureBinding._flushPointerEventQueue (binding.dart:296)
GestureBinding._handlePointerDataPacket (binding.dart:279)
._rootRunUnary (zone.dart:1370)
_CustomZone.runUnary (zone.dart:1265)
_CustomZone.runUnaryGuarded (zone.dart:1170)
._invoke1 (hooks.dart:182)
PlatformDispatcher._dispatchPointerDataPacket (platform_dispatcher.dart:282)
._dispatchPointerDataPacket (hooks.dart:96)

[ondramastik]

You probably have a ReorderableListener without a _ReorderableItemState child, that's why it's failing.