It crashes when I press play or create new world and IT is not modded

Put the summary of the bug you're having here

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

What actually happened was...:
I open minecraft press play, make new world and then boom my minecraft crashes I uninstalled it then re installed it and that only worked for the first world I created Thought it works with multiplayer

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2.select new world or create new world it starts to load then crashes
3. ...