In classdef, how to call a static method from an other class P.c.averages()?

Hi,

I am moving to 2018a from 2016a and found this error: External converter methods for package-qualified classes not supported. Define 'obj.averages' converter for class 'P.c' in the classdef block. the method averages is defined in a super class of P.c in a separate file. How to resolve this? Thanks for any input. Jennifer

[JFz]

All I am doing is to call a method in superclass in classdef block. It worked fine in 2016a.