After flying around the world for a while in creative, a crash will randomly occur when loading new chunks.
https://gist.github.com/ChiefLogan3010/e3efa6b3eff61b7808c1177abfd4a939

I've intentionally kept stucture generating mods to a minimum in order to make players unable to skip early game through loot. The only mod I can think of that messes with villages is Better With Mods, which has a hardcore feature which disables certain blocks in villages in a configurable radius from spawn in order for them to look looted. I have disabled the Immersive Engineering villager house in the config, so it hopefully shouldn't be that.

With regards to the pack, it's an in-dev hardcore pack that intends to make early-game a lot harder and more immersive.

Did 1.12 change the format that Villages are stored in? The village data (which used to only provide positions, I guess) is providing a DeletedStructures tag, now, which is then blindly looped over and attempts to create a WatcherPos out of.

I'm trying to recreate this with Antique Atlas 1.12.2-4.4.6 and BiomesOPlenty 1.12.2 7.01.2330. I've come across some villages, but haven't gotten any crashes. About how frequently does this occur?

I doesn't happen with every village, so I'm not sure whether it's certain structures within villages or certain types of wood that villages are based on. It's also possible it's not anything to do with BOP but another mod that messes with villages. Regardless of the cause it seems random how often it occurs, sometimes upon world load and sometimes after 5 minutes of flying in creative.

I'll do some more exploring then.

Apparently fixed by #169.