Is your map modded.
Try doing it on a clean map, then using entity or insolence drag it over to your modded map. That keeps the modded map from bugging out.
Well If its not modded I still suggest that you do it the way I just explained. Makes sure that your map that's gonna be modded doesn't have a 1000 holes in it.
I would say it's either your dark matter, your model, your map, or your directX.
Get the map from the disc so its a 100% clean.
Go to the utilities and find the latest dark matter.
I wouldn't think that your models the issue.
Download the latest DirectX.