Halleluja! No, before lightbuild, and because i keep ‘affects world’ in ‘Light’ off it stayed black. I created a cool lighting effect that i wanted to keep.
Anyways i think i solved the problem. For the terrain in the lighting setting i set Static Lighting LOD to 2. The up popping dialog gave me the hint. (to prevent crashes of lightmass set to 1 or 2) After light rebuild:
Now i saved my special lighting effect and can see finally grass on the terrain. Puu!
Thanks for all the help.