Minecraft keeps crashing when trying to join A world or A server.

Minecraft keeps crashing when trying to join A world or A server.

What I expected to happen was...:
Minecraft to normally let me join the world/server.

What actually happened was...:
Minecraft crashed

Steps to Reproduce:
1. Get minecraft on the select [multiplayer,Singleplayer,other] Screen
2. Click on single player or multiplayer
3. Try to join a world [I crashed]