"Bad leaf ambient for leaf ####" And now my map has no lighting

My map is pitch black. When I move into a lit area my view model is lit properly, but all of the textures are black.

this appears a couple thousand times in the compile log;

Bad leaf ambient for leaf 8

Why is this happening and what do I do to get rid of it?

When you use http://www.interlopers.net/errors/ it shows that the problem might be “zero area child patch”.

Alright, I fixed it. The “zero area child patch” errors were caused by a buggy surf ramp I had added, and the bad leaf ambient errors were because of water being inside a func_viscluster, and maybe from a lot of faces having low lightmaps

Those combined = broken map I guess.