Hammer Texture Problems

For some reason the textures all show up as partially translucent, or completely gone. (In the BSP, shows up fine in ZP:S)

I’m configured to map for Zombie Panic! Source by the way.

-update-

After shining my flashlight I discovered that none of the textures are gone, but are extremely dark. I’ll fix the lighting, but some of the textures still show as transparent.