That would explain it.
Hmmm. I'm still having problems with this civ - instead of crashing immediately after setting civilizations it does so during the "Finalizing sites" phase...absolutely no clue as to why, errorlog doesn't show anything wrong with the civ from what I can tell.
EDIT: Ok, I'm at a loss. I consistently get crashes in the same moment of worldgen regardless of what I do, and I know it's because of this civ since after removing it I could generate a world no problem.
I changed it so instead of dark forts they live in fortresses like dwarves and eventually normal human towns - still crashes.
I removed restrictions on which caste of the demon race can become which position (previously, i.e only annihilan, nathrezim and eredar could become "masters/mistresses", only annihilan could become generals, only nathrezim could become lieutenants and only ered'ruin could become captains) - still crashes.
Changed biomes - still crashes.
Changed things around in the creature file itself so all demons live the same amount of time regardless of caste (previously some would live longer while others would never die of old age) - still crashes.
Copied the dwarf entity file and replaced everything over again so that it'd fit the demons instead - still crashes.
Anyone mind taking a look at this for me? I bet it's something really obvious that I'm missing but I'd be glad if someone else could test this out too and see if they notice anything.
https://dl.dropboxusercontent.com/u/62904003/demonciv%2Bcreature.rarErrorlog doesn't really show anything conclusive, no entity errors, none of the creature errors appear major in any way (they work fine in arena tests - no crashes).
What's weird is that on larger worlds I always get the same crash during "Finalizing sites". On smaller worlds it sometimes happens but not always - that's another thing that's confusin me.
EDIT 2: Weird, I'm assuming it's to do with the creature itself right now...I copied the human civ and just added the demons without changing anything else, and yup, it crashes.
EDIT 3: Crap, I forgot to add the body parts - updated the file now.