The new update wont allow me to play servers

Put the summary of the bug you're having here

What I expected to happen was that i would play normally...:
Describe what you thought should happen here

What actually happened was i couldnt play on servers...:
Describe what happened here i logged on to the server and after 5 seconds my minecraft crashed

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...Let me play on servers
3. ...