GMod freezing/crashing during multiplayer


I have recently been playing on the Pulsar Effect Serious Roleplay server using the Evocity2 map. I was able to connect to the server fine, but then every 20-30 minutes into gameplay Garry’s Mod would suddenly stop and quit to desktop, if I restored it, it would be all black. I would get this error message:

The map runs fine on single player mode, but this server uses weapons and models from CS:S, which I don’t have. This doesn’t appear to be a problem, because GMOD doesn’t crash when someone uses a model from CS:S, it just becomes the “ERROR” model.

But recently, trying to debug the problem, I can’t even connect to the server, GMOD stops loading and just stays at “Retrieving server information”. If I cancel the load and quit GMOD, I get the above image and this one too:

Singleplayer is running normally.

My drivers and DirectX are fully updated, and there seems to be no problem with the server. I have restarted my computer and Steam many times, and removed old files, but I still get the crashing.

Any suggestions are accepted.

Lock please, server related issue.