“TypeOf…Is Child” from Parent causes broken Excel file

Question

I\'ve been tracking down this issue for several days, so I thought I\'d post it here to help others with the same problem, as well as learn more about the cause. I\'ve simpl

Answer 1

VBA does not support class polymorphism.

I think you are misunderstanding the purpose of the keyword Implements.

It's used when you want a class to implement an Interface - not another class ( well, at least not literally because an Interface in VBA is another class module object )

See this answer for better understanding of the Implements keyword in VBA

Also refer to this for info about VBA polymorphism