Put the summary of the bug you're having here

What I expected to happen was...:
I would push the expand screen button (green +) on left corner of minecraft launcher to make screen larger

What actually happened was...:
screen went gray and a scary note that said shut down your computer appeared instead!

Steps to Reproduce:
1. launch mine craft
2. when player screen comes up before you actually begin to play by entering game push expand screen button.
3. gray screen comes up to force computer shut down.
4. Must actually shut down computer manually and then restart after screen goes black.