About time lol. I did the initial port of rend2 MP to SP, while SomaZ and uniqueone helped out with a few issues I had. SomaZ is now adding & tweaking things, so it's now his baby. So I've changed all entities to be black when there's no lighting unlike vanilla, which has a minimum light. Other than that, I don't think I've made any other DF2-specific changes to the GL2 renderer. I pretty much leave renderer stuff to SomaZ now, so he has everything how he wants it without interference. About that error. It could be an unsupported shader blend?