SuperFlat

Put the summary of the bug you're having here

What I expected to happen was...:
Describe what you thought should happen here
It should've generated a normal superflat world, but instead it generated a very weird one.
What actually happened was...:
I generated a SuperFlat world and it went wrong
Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. Create a default world.
3. Delete it.
4. Create a superflat world and it will generate a very weird superflat world
Oh and can you give me a minecraft account?I could try finding more bugs.