[BUG]: Error Widget

[CleoMenezesJr]

Null check operator used on a null value
#0 SelectableRegionState.startGlyphHeight (package:flutter/src/widgets/selectable_region.dart:1211)
#1 SelectableRegionState.contextMenuAnchors (package:flutter/src/widgets/selectable_region.dart:1093)
#2 new AdaptiveTextSelectionToolbar.selectableRegion (package:flutter/src/material/adaptive_text_selection_toolbar.dart:177)
#3 SelectionArea._defaultContextMenuBuilder (package:flutter/src/material/selection_area.dart:96)
#4 SelectableRegionState._onAnyDragEnd. (package:flutter/src/widgets/selectable_region.dart:694)
#5 SelectionOverlay.showToolbar. (package:flutter/src/widgets/text_selection.dart:1426)
#6 ContextMenuController.show. (package:flutter/src/widgets/context_menu_controller.dart:65)
#7 _OverlayEntryWidgetState.build (package:flutter/src/widgets/overlay.dart:398)
#8 StatefulElement.build (package:flutter/src/widgets/framework.dart:5592)
#9 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5480)
#10 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:5643)
#11 Element.rebuild (package:flutter/src/widgets/framework.dart:5196)
#12 BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2904)
#13 WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:989)
#14 RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:448)
#15 SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1386)
#16 SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:1311)
#17 SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:1169)
#18 _invoke (dart:ui/hooks.dart:312)
#19 PlatformDispatcher._drawFrame (dart:ui/platform_dispatcher.dart:399)
#20 _drawFrame (dart:ui/hooks.dart:283)