Cause
This error occurs if the method being compiled, which is defined on a subschema copy class, does not have a compatible signature with a method of the same name which exists in a subclass of the subschema copy class in some other schema.
The other method exists in the schema containing the root type of method being compiled or in one of its subschemas, as shown in the following example:
In the following example of a SomeSchema schema, ClassB implements a meth(): String; method.
In a subschema of the SomeSchema schema in the following example, ClassA attempts to implement a meth(): Boolean; method.
Action
Change the method signature to be compatible with the signature of the existing method.
