TypeError: type 'String' is not a subtype of type 'int' of 'index'

[sentry-io]

Sentry Issue: GLUT-ASSISTANT-N-X

TypeError: type 'String' is not a subtype of type 'int' of 'index'
  File "string_patch.dart", line 274, in _StringBase.[]
  File "update.dart", line 61, in UpdatePageBodyState._next.<T>
    AppData.persistentData["newVersion"] = result["newVersion"];
  File "framework.dart", line 1203, in State.setState
    final Object? result = fn() as dynamic;
  File "update.dart", line 60, in UpdatePageBodyState._next
    setState(() {
  File "update.dart", line 106, in UpdatePageBodyState.build.<T>.<T>
    getUpdate().then((value) => _next(value));
...
(6 additional frame(s) were not displayed)

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