Server, laggs then crashes

Put the summary of the bug you're having here

What I expected to happen was...:
I could play on the server and have a happy day!

What actually happened was...:
I logged on to the server, and it lagged, and all of a sudden it said "End of Stream", I tried logging on to the server again, and once I started to move around, It lagged, and this time the whole game crashed!

Steps to Reproduce:
1. Log onto the server "mcctf.com"
2. Try to move around
3. It will lag and either return to multiplayer screen with "End of Stream" Error or the whole game will crash