Crash when selected world

Put the summary of the bug you're having here

What I expected to happen was it loads up fine but when I select a world it crashes on me. Also I have no internet connection at all...:
Describe what you thought should happen here

What actually happened was...:
Describe what happened here

Steps to Reproduce:
1. Launched Minecraft
2. Clicked play offline (only option)
3. .Loaded up single player world and then it crashed

Note, it is 1.8.7, the form wouldn't let me choose that...but it is 1.8.7