Error with DimensionType (I think)

[CrazyPanda741]

I'm working on my addon, and cannot get past one error. It's saying something about villages and I have no idea what it means.
Error Link: https://pastebin.com/YmLbLBS9
GitHub: https://github.com/CrazyPanda7/Trappist-1_Mod/tree/Trappist1bWorldGen