i tried to load minecraft but when i got the mojang screen t kept crashing plz help

Put the summary of the bug you're having here

*What I expected to happen was...:*minecraft to load but it kept crashing over and over again
Describe what you thought should happen here

*What actually happened was...:*it crashed and said minecraft has run out of data
Describe what happened here

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