minecraft server crashes minecraft

Put the summary of the bug you're having here

What I expected to happen was...:
Describe what you thought should happen here
i would come onto the server
What actually happened was...:
Describe what happened here
minecraft crashed
Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...i log on to a server called eu.thenexusmc.com (1.7.9)
3. ...then before i log onto the world minecraft crashes!!! please help