i logg in and eerything and then i get on a server 5 sec later it tell me there is a bug outside of java and brings me to a play screen output

Put the summary of the bug you're having here

What I expected to happen was...:
Describe what you thought should happen here

What actually happened was...:
Describe what happened here

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