I tested it briefly on the 13w39a version and the issue seems fixed. I can change Anisotropic filter just fine.
I also get the same crash when I join my server, but not a single player world. The curious thing is that if I try 6-10 times to join the server at the end it works.
I tested it briefly on the 13w39a version and the issue seems fixed. I can change Anisotropic filter just fine.