[Crash/Bug] Rendering Video Demos

I recorded a demo like normal, then I got to Main Menu > Demos > [the video i wanted to render] > Make Video. Before it begins rendering, Gmod crashes with the following error: Lua Panic! Something went horribly wrong! [attempt to index a nil value].

Does using custom models cause this problem, or am I not the only one who gets this error. Here’s my MDMP file: http://www.mediafire.com/?du5g8kog2l7bw7v

In case you wonder what custom models I’m using, I’m using the Metropolice Pack v5 with Easy Animation Tool and Easy Bodygroup Tool, all from Workshop.

That’s been happening to me too, I also have the Metropolice Pack but I doubt that would be it.