TypeError: type 'Null' is not a subtype of type 'String'

[sentry-io]

Sentry Issue: GLUT-ASSISTANT-N-3C

TypeError: type 'Null' is not a subtype of type 'String'
  File "queryClassRoom.dart", line 255, in QueryConditionCardState.build
    hint: Text(query["weekOfSemester"]?[whichWeekSelect], style: TextStyle(fontSize: 14)),
  File "framework.dart", line 5729, in StatefulElement.build
    Widget build() => state.build(this);
  File "framework.dart", line 5617, in ComponentElement.performRebuild
    built = build();
  File "framework.dart", line 5780, in StatefulElement.performRebuild
    super.performRebuild();
  File "framework.dart", line 5333, in Element.rebuild
    performRebuild();
...
(18 additional frame(s) were not displayed)

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