Failed assertion: line 3927 pos 14: ‘_dependents.isEmpty’: is not true

I recently had the same exception when I was trying to navigate to another route from a Stateful Widget. Turns out I had forgotten to add the line super.initState(); at the start of my widget’s initState()

Once I change it to this it worked perfectly

 @override
  void initState() {
    super.initState();
    ....
  }