[Solved] Dart throws LateInitializationError even when I initialize variables in initState

This is declaring a local variable: AnimationController _animationController = AnimationController(vsync: this, duration: Duration(milliseconds: 500)); What you want is assign to your existing class member variable: _animationController = AnimationController(vsync: this, duration: Duration(milliseconds: 500)); solved Dart throws LateInitializationError even when I initialize variables in initState