Issue Description:

Game crashes with an index out of bounds exception when generating a world.

Steps to reproduce:

1. Install Biomes O plenty 1.9
2. Create a new world of BoP worldtype
3. Crash

Additional Information:

http://pastebin.com/17VPBBW5
(No screenshots, nothing to show other than a crash log)

Affected Versions (Exact numbers, do not use "latest"):

• Biomes O' Plenty: 4.0.2.2018
• Minecraft: 1.9
• Forge: 12.16.1.1887

I've discovered that this problem is mostly unrelated to BoP.