game screen other than HUD goes blue and game crashes whenever I try to play

Put the summary of the bug you're having here

What I expected to happen was...:
Describe what you thought should happen here

What I expected to happen was.... I would open my world and play my game

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

What actually happened was.... the game screen went pale blue (color of minecraft sky) except for the HUD and the game window closed

Steps to Reproduce:
1. open minecraft launcher 0.9.1 (Dev)
2. click 'play'
3. Hit 'singleplayer' in the game menu
4. Select your world and hit 'play selected world'