MDC-104 Flutter: Material Advanced Components - error with Category.all in Backdrop()

[PoppaBart]

I have the following error when in // TODO: Change to a Backdrop with a HomePage frontLayer (104).

The argument type 'Category (where Category is defined in D:\FlutterDevelopment\Projects\materials_101\lib\model\product.dart)' can't be assigned to the parameter type 'Category (where Category is defined in D:\flutter\packages\flutter\lib\src\foundation\annotations.dart)'. dartargument_type_not_assignable
product.dart(1, 6): Category is defined in D:\FlutterDevelopment\Projects\materials_101\lib\model\product.dart
annotations.dart(40, 7): Category is defined in D:\flutter\packages\flutter\lib\src\foundation\annotations.dart
enum Category