Nether generates in strips if it doesn't crash

Put the summary of the bug you're having here

When entering the nether after using the World Debug generator, the game freezes, then immediately afterward it crashed.

What I expected to happen was...:

The default nether would generate, or maybe a flat nether

What actually happened was...:
The game froze, followed by a breif glimpse of a weird, farlandic type nether, then crashed

Steps to Reproduce:
1. Create a Debug World with the Debug generator
2. Enter the nether