Map attempt crashes GMod

[>>oubliet]

I would've posted this in the Mapping section but garry said this is for "scripting and mapping" so ..

I'm working on a project that needs a map, I'm not heavy on the mapping side mainly scripting so I was playing about with hammer for a bit.

My problem is that the map crashes Garry's Mod when I load it on the client, it doesn't crash at the "Loading map" stage but just after the game has launched
it will simply close and create a crash dump file.

The crash dump file contains no useful information.

I checked the compile log in Interlopers error finder and there's one Warning: "could not find lights.rad in lights.rad", surely this couldn't cause what I'm seeing here.

I did my research, I can't seem to find any helpful information related to this.

I know you can't automagically find out what's wrong and tell me how to fix it, my question is simply;

What should I do from here? When you've seen this behaviour what do you look for?

Thanks, any help is appreciated