I click on single player and open one of my own servers but then the whole game quits and goes to the Game Output (pictured below). The same thing happens for multiplayer and I can't join any of the multiplayer servers. I've tried using different game versions but the same things keep happening.
My Minecraft won't let me join anything?
Guest 05.05.2016
Do you get a crash log? Go to your minecraft folder and you should have a folder called logs. Can you copy and paste the crash log to http://pastebin.com/ and give me the link so I can look at it? Much easier than doing back and forth messages trying to find out what's wrong.
Ducky 05.05.2016