So I'm not a huge modding guru, but I'm starting to understand it a little bit.

I recently installed MGSO 3.0 and love it, and am trying to get the house mod, Arvs-Spelun to work as well

but I keep getting an error message in-game:

Meshes\Ar_Sp\D\doors.nif

Error.NIF

what does this mean? and what can I do to remedy it? I've tried several forms of extraction (7zip and WinRAR) and reset my Load Order (though that was through MGSO's default load order program)

thank you