Lighting glitch

[zahmbie1]

I have a light_environment in the map and it works, but the lights cast a grid

Here is what it should look like, according to Hammer++

Here is what it looks like ingame

 

[Pocket]

Whatever material you used is pointing to a $bumpmap that doesn't exist, so it's replacing it with a the default fuchsia-and-black checkerboard used for missing textures.