blender error importing nif

Hello to anyone kind enough to read this.
I’ve spent the better part of today trying to import a .nif into blender and I just don’t know where to look anyone or what to do. I started off trying to prep the .nif file following the guide from here . After that i followed the steps from this video so that it recognizes the nif files. Yet when I try to import them into blender i get an error



I just started learning all this today and figured the first step should be learning how to import/export and such to make it easier down the line but now I’m not so sure, haha.

Any help is much appreciated and please explain things like you’re talking to a simplton, haha.

Thanks ahead of time,
Cgod

Is that a game file? You can also get support in the game engine section if no one here can answer.