I exported the bsa for Chinese Stealth Armour to edit the mesh. Then i exported it from nifskope as a .obj and imported it into 3ds max to edit it. When i load it up, it says that i'm "missing external files". Can i just continue with this or do i have to fix it?

Why not just import from .nif ?

and importing from .obj usually looks for the accompanying .mtl file as well which I do not thing NifSkope generates -> but it can be ignored you will just have to re-do all of the data that .mtl file holds -> not sure exactly what that details as I am not up on the exact specifics on the .obj/.mtl formats.

I'm pretty sure nifskope does generate a mtl along with the obj.

Why are you doing it the old pre-Fallout-compatible NIFTools plugin way? Seriously, it's so much easier to just directly import the NIF. That way, you don't lose the skinning data either.

Are you having problems with the import prompt not being able to find the rigging skeleton NIF?

no, he is using 2011. so it's likely an install issue.

and I already told him that apparently you can install the 2010 nifplugin in the right directories, but under the max 2011 folders instead of the 2010 ones. Apparently it works according to someone on the oblivion CS forum.