Hey, I had the Fatal Error 2 Null happen on Minecraft. I fixed it so I thought I should put up how to fix it in case it happens. It starts out you'll try to log in and it will say Fatal Error 2 ( Null, or at least something close to that. Don't waste your time trying the in browser play, the same thing will happen. Try updating Java. If that doesn't work, which it didn't for me, delete your .minecraft folder. You will have to recreate or redownload your worlds, but it will fix it.