The game crashed after I tabbed out to check Discord.. somehow a light value was -1, idek.

Mod version: 1.12.2-3.4.9.8
Crash report: pastebin:crash-2018-03-17_17.18.18-client.txt

This may be fixed with the 3.4.9.9 version I am finalizing. I saw something similar in dev and it was really strange.

I found a bug too, auroras appear on the ground instead of in the sky.

Are you in Overworld or a modded dimension?

Pushed v3.4.9.9 to CurseForge for the crash.