Traceback (Most recent call last) problem

I don’t know how to fix it, it is the third time i use blender but that never happened to me,how i fix it?

(i was fixing the model with CATS and that happened)

The Blender developers do not maintain this add-on, any bugs or errors should be reported to the author of the add-on.

Bugs in Blender also should not be reported on this forum, but rather in the bug tracker: