No lightmap after baking and black Shadows/Terrain.

After I bake Lightmaps for about 24h, My Terrain is black, my shadows are pitch black, and it also says 0 B No light maps in the Lighting window. It seems it does not create any light maps. What is going on here, how do I get rid of the black terrain and black shadows now? Also in my Cave where it is used to be dark and creepy is now heavenly peaceful (a very lid cave that looks like an ice cave).