Cause
This error occurs if you attempt to apply certain changes to a class that is defined in the superschema.
Only a limited range of operations is permitted on classes that are defined in a superschema. New methods and constants can be added to those classes, but no other changes or additions are permitted.
The following operations are not permitted on classes that are defined in a superschema.
Adding new properties.
Modifying the signature or the implementation of existing methods.
Adding or modifying documentation text.
Adding new keys to a collection class.
Defining a constructor (create) or a destructor (delete).
Action
Remove the lines that caused this error. If you need to modify or add to a superschema class, load those changes into the superschema that owns the class.