My brushes' textures look fine in Hammer, but are suddenly black in-game

[Azoloch]

I have been looking all over Google, but I just can't figure it out. I am making a test map for a gamemode in Garry's Mod. Everything went well, until I did the final compiling. Almost all of my textures are suddenly [URL="https://dl.dropbox.com/s/6uk9jkr9nxc2en2/2014-01-29_00002.jpg"]black in-game[/URL], despite [URL="https://dl.dropbox.com/s/lzx57z24s6796ga/Screenshot%202014-01-29%2021.17.53.png"]looking fine and dandy in Hammer[/URL] (I have changed the texture on the box as well to experiment). Nothing I have encountered and tried seems to fix it, either.

I'm at a loss. Can anybody point me into the right direction?

Thanks in advance.

[editline]29th January 2014[/editline]

I've fixed it. Somehow my lighting_environment entity was causing this.