I cant get on to any servers or made up worlds without it coming off in 2 seconds ?

Put the summary of the bug you're having here
It wont let me get on to any servers or made up worlds.

What I expected to happen was...:
Describe what you thought should happen here
I thought it was a one of thing but instead it wasn't.And I still cant get on to it since a week??

What actually happened was...:
Describe what happened here
Well,i went on to it a week ago and it came on but after about 2 seconds it went straight on to something with lots of writing on it and it had said on one line a "Fatal Error".

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...Get rid of it
3. ...get rid of it