Answers for "Failed assertion: line 198 pos 15: 'initialValue == null || controller == null': is not true."

Failed assertion: line 198 pos 15: 'initialValue == null || controller == null': is not true.

// In class level 
final controller = TextEditingController(text: "Your initial value");

Widget build(BuildContext context) {
  return TextFormField(
    controller: controller, 
    // ...
  );
}