https://cdn.discordapp.com/attachments/154261184701267969/799351440803758100/2021-01-14_12.56.36.png

beautiful

Edit: Ah I just noticed that the below cave is called "Crevices", doesn't change much though because i also saw the same issue with "Mega Caves".

Didn't open a separate ticket because another possible issue seems kind of related, but I can open a separate one if preferred. (my line of thinking - perhaps the monster boxes get spawned on caves that existed there previously and the large caverns simply "delete" normal blocks or something without taking into account existing structures)

The large caverns also seem to cut or entirely delete structures, e.g. from "Dungeon Crawl" if those happen to overlap. I also saw some Mineshafts (e.g. from repurposed structures I think) being cut (so only the bottom half of a shaft remained and the top half of the shaft was just gone)

Screenshot (Dungeon Crawl dungeon being sliced apart, includes F3 overlay for MC version aswell as forge version and position)

Worldgen Settings file (if needed for reproduction, needs to be renamed to .json probably, github limitation)

• worldgen_settings_export.txt

Modfiles used

• AutoRegLib-1.6-47.jar
• DungeonCrawl-1.16.3-2.2.4.jar
• Quark-r2.4-294.jar
• repurposed_structures-1.16.4-2.3.4.jar