I made a map and put some Derek's weapons in it to test my graphics. I can pickup those weapons normally. If I try to put them in my hand, (f.e. if the M16 was in slot "3", and if I pressed 3), the game crashes and I get the following error:

Some weapons, thou, not a-lot, work without any crashing:

(Screenshot messes up the graphics, better in-game)
Any help would be appreciated, thanks.