Crash when loading up a customized superflat world with the bottom layer bedrock and the next layer farmland.

When I right click on armor, it puts it on the next layer up. For example, tunic goes to the helmet spot, leggings go to the chestplate spot, etc.

Minecraft lagged out on me(which it never does) when creating a costimized superflat world when editing the superflat preset to be different blocks