When i started up superflat and made a certain preset (a specific one) the game crashed

I thought it should open normally and i could build

Minecraft crashed completely

1. Start Minecraft
2. Start a new world
3. Change to creative mode
4. change to superflat
5. Edit the superflat layers
6. Make the preset say this exactly "64x64"
7. Click Use Preset
8. Minecraft Crashes