Everytime I play in any of my worlds in 15w31a, b or c, I see nothing but a black screen with my hotbar. I can walk around, break and place blocks, hear sounds, see the id's of the blocks i'm looking at in the F3 screen, but the screen stays black, even with nightvision or spamming torches. I do not know what caused this game-breaking bug, but it needs fixing. Being blind is a terrible disability.