Minecraft crashes mid game

It happened for 2 days straight now. Basically since I updated to the pre-release. I can play great for a while. I played about 30 minutes until it happened the first time. Tried connecting to the same server again and I get in and immediately it crashes. I can no longer even connect. It allows me to click connect but goes straight to the error report. I have attached 2 files. One crash after a while. The second is the one I get after not being able to connect.