Garry's Mod crashes whenever I see a certain Player Model.

Okay, so I enjoy this DarkRP server, and it has a Hitman system. However, whenever I near or see the Hitman, I crash, Either it has too many textures or it is an unknown playermodel. Here is the crash report: http://www.filedropper.com/hl2140713crash201538t23222c0. I would like to know how to fix this annoying and exploitable issue.