Issue Description:

Command /ct biomes doesn't work.

What happens:

Output in chat is "An unknown error occurred while attempting to perform this command."
Output in crafttweaker.log is simply the line "Biomes:" with no output after it, there is nothing relevant to the error in that log.

latest.log file excerpt

https://gist.github.com/Geethebluesky/5f4993670d6438e79d3e9f22f80c8b7d

Affected Versions (Do not use "latest"):

• Minecraft: 1.12.2
• Forge: forge-1.12.2-14.23.3.2678-universal.jar
• Crafttweaker: CraftTweaker2-1.12-4.1.8.jar

Possibly related:
#526 which is fixed in dev

fixed by that commit anyway