I have tested the whole mesh as one piece, I did split it up into several single pieces, I gave the mesh a wireframe with collision by triangles, like vanilla meshes have, but nothing did help this time. I had such problems long time ago and back then just a simple clean export from 3ds max fixed the issue. I have max myself, but because of some reason the official nif exporter makes the program crash immediately!!!
Could one of you max users please just import and export the nif again, pleeeeeeeeease!!!
THX, TheDaywalker!!! :rock: