my worlds are not working when i creat a new world

Put the summary of the bug you're having here i am trying to cear a nwe world but when i do it crashes

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

What actually happened was...:
Describe what happened here
i was trying to creat a new world but when i do it it crashes

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...creat a world
3. then it crashes