MInecraft opens to mojang screen then crashes

Put the summary of the bug you're having here
minecraft opens to the mojang screen then crashes
What I expected to happen was...: for it to open
Describe what you thought should happen here
i thought it would open
What actually happened was...: it crashed
Describe what happened here

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...
3. ...