OK, the Creation Kit likes throwing error markers at you for bad .nif's without telling you what the error(s) is/are.

NifSkope has no sort of error detection at all.

It's really annoying to get these errors and not being able to resolve them quickly, because without 5 years of NifSchool you won't know what's the cause of them!

It would be so nice to be able to click a button like "Test for Skyrim" and have it read back a list like:

Error: 'NiHeader' value for 'User Version 2' is incompatible with SkyrimError: 7 'NiMaterialProperty' is incompatible with SkyrimError: 5 'NiTriStrips' is incompatible with SkyrimWarning: 3 'bhkRigidBody' variable list 'Unknown 7 Shorts' value#4 should be set at '0'Warning: 3 'bhkRigidBody' variable list 'Unknown 7 Shorts' value#5 should be set at '0'Error: File name exceeds character limit

But, that's a pipe dream... Anyway /rant

What are you trying to do exactly?

I don't know what any of that means but my game kept crashing because 2 names were the same since Nifskope doesn't rename a pasted branch, it just takes the name of an old one.

Probably doesn't apply to you but give it a look.