Whenever i type on servers my minecraft exits out and crashes

Put the summary of the bug you're having here

*What I expected to happen was to type something and send it
Describe what you thought should happen here

*What actually happened was my minecraft exited out and crashed
Describe what happened here

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...go onto a minecraft server
3. ...try and type something