cant type on chat

Put the summary of the bug you're having here

What I expected to happen was...:
i was playing mutiplayer in a 1.mc-war.net when i went to type a message not a command it crashed

What actually happened was...:
when i type in the chat i get logged off and sent to the "minecraft crash" screen.

Steps to Reproduce:
1. dont know how to trigger the bug
2. ...
3. ...