I've been working on a GMOD map, and I wanted to base its skybox off of one of my CSGO maps. So I decided I'd open it in the CSGO SDK and put in the light_environment, and when I tried to load it back in the Source SDK, it wouldn't work. I tried removing the light_environment, and the same thing happened...
How can I get the map to open in Source SDK? I even tried running the .vmx to no avail!