Crashing when I hit multiplayer

Put the summary of the bug you're having here
Crashing
*What I expected to happen was...:*I could play online
Describe what you thought should happen here
That you guys should fix it since your a part of minecraft
What actually happened was...: It keeps crashing
Describe what happened here
It crashes
Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ... Click multiplayer
3. ... Crashes