when i launch minecraft it goes to the mojang screen like normal then it closes for some reason.

Put the summary of the bug you're having here

I expected minecraft to launch
Describe what you thought should happen here
I thought it should launch
What actually happened was...:
Describe what happened here
It launched then exited unexpectedly
Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...I
3. ...