[HELP] Lights don't works! BLACK textures

Hello i have a big problem on my map.

Here is how it’s looks like In Game:

Does anyone know how to fix this please?

[editline]24th April 2015[/editline]

This problem only happens to me when i set the : Far Z Clip on the env_fog_controller.

This is caused by a leak, a 3D skybox, or vrad simply giving you the middle finger because of something in your map.

Hey, this is probably a leak. If you know your skybox is sealed, try checking if you placed something outside your skybox. Maybe there’s something sticking out?