Quote from CookieMonstr
I've been getting this after I installed the last (A6) Optifine. The client is full vanilla, and this is the only mod on.
Why isn't it working? I don't understand ANY of this...
1.5.1 is NOT COMPATIABLE with 1.5. Do not use A6 on a 1.5 client. This should fix black screen problems for most people.