Unhandled Exception: Exception: Animated list state not found from GlobalKey<AnimatedListState>

[allanfann]

My code:

for (var element in _rootNode.childrenAsList) { if (element.key == parentKey.toString()) { try { element .add(TreeNode(key: context.uid.toString())); } catch (e) {} return; } }

Exception:

[ERROR:flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: Exception: Animated list state not found from GlobalKey<AnimatedListState> #0 _AnimatedListState.insertItem tree_view.dart:495 #1 AnimatedListController.insert animated_list_controller.dart:65 #2 AnimatedListController.insertAll animated_list_controller.dart:70 #3 AnimatedListController.expandNode animated_list_controller.dart:116 #4 AnimatedListController.handleAddItemsEvent animated_list_controller.dart:208 #5 _RootZone.runUnaryGuarded (dart:async/zone.dart:1593:10) #6 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:339:11) #7 _DelayedData.perform (dart:async/stream_impl.dart:515:14)