I think about this there are many other topic in the comunity available.
I think your robot model is a super component.
Do it in this way and it should work:
As library root you need to select the folder containing fupa components.
If this folder is not available, you can do do two things:
1. Open your model in Robcad and break the connection between robot and fupa.
2. Go to KUKA Download Center and load the robot model which contains fuba components.