Very, VERY peculiar problem : I have a map that loads COMPLETELY pitch black. I've tried adding light_env entities, env_lightglow entities, and yet, NOTHING.
It's just pitch black. I made it correctly, in the sense that I have the skybox, and everything else, yet it's still really wierd.
It's not even the "hole in the world, laggy glitch thing", it's more of a "whole map is really dark", type thing. If you shoot, the muzzle flash illuminates the area around you for a slip second, but that's it.