each time i try to connect to a server on version 1.7.9 i get a crash report

Put the summary of the bug you're having here

What I expected to happen was...:
Describe what you thought should happen here
that i would connect to the server
What actually happened was...:
I got thrown back to the launcher screen with a crash report

Steps to Reproduce:
1. run your game on 1.7.9
2. try to connect to a server
3. get a crash report