Talon685

If you still need help, go here http://www.webupd8.org/2012/09/install-oracle-java-8-in-ubuntu-via-ppa.html and follow the instructions (It can install Java 7 as well). I don't know if it'll fix your problem, though. I'm running Debian 64 bit and having the same issue. I tried getting a new Minecraft.jar and placing it in the cache but that still doesn't work. However, vanilla works just fine.