Crashing while i press mutiplayer button

Put the summary of the bug you're having here

What I expected to happen was...:
I was playing and i pressed mutilplayer and the game crashed

*What actually happened was...:*the game just crashed pressing mutiplayer
Describe what happened here so i opened Minecraft.exe/Minecraft and i pressed mutiplayer and crashed

Steps to Reproduce:
1. i opened minecraft launcher 1.6.5
2. .. then clicked 1.8 went into the game
3. ... I pressed mutiplayer crashed