What is the difference between a 'Parent Class' and a 'Native Parent Class'?

… and what does it mean when they are different?

In the image below the ‘native parent class’ is Actor, while the ‘parent class’ is GRD_INTR_BaseStructure.
[I am currently receiving errors when I try to compile that tell me GRD_INTR_Empty is not a valid subclass of GRD_INTR_BaseStructure][1].

Is this related, and is there a way to change the native parent class?

Parent Class is the base class of the object.
A native parent class is a parent class defined in C++.

Can it be/should it be changed to match the parent class?

Do you think it is related to my subclassing problem in my other question?

Is it suppose to be different? Or is something bugged?

It’s supposed to be like that.

If you look at a native (C++) class in the Content Browser, you’ll see that the Parent Class and Native Parent Class match. Similarly if you derive a Blueprint class from a C++ type, they will also match.

They vary when you derive a Blueprint class from another Blueprint class, as your Parent Class is then your Blueprint type, but your Native Parent Class is still the C++ type that your parent Blueprint class was derived from.

Functionally this information is only used to show you the correct icon in the Content Browser without having to load up your parent Blueprint class (as that can be very costly).