invalid_visible_for_overriding_annotation

The annotation 'visibleForOverriding' can only be applied to a public instance member that can be overridden.

The analyzer produces this diagnostic when anything other than a public instance member of a class is annotated with visibleForOverriding. Because only public instance members can be overridden outside the defining library, there's no value to annotating any other declarations.

The following code produces this diagnostic because the annotation is on a class, and classes can't be overridden:

import 'package:meta/meta.dart';
​
@visibleForOverriding
class C {}

Remove the annotation:

class C {}