@羽泠洛 Sorry for being away for so long. I was in crunch mode in my RL project and didn’t have time to check Steam. I think you put both of my mods at the same time. Try to uninstall the old ones for 1.4/1.5.

"itself [duplicates: 1] of packageld [emitbreaker.mim.wh40k.aa.core] in Active and/or Inactive lists."
There has same issue in "MIM Warhammer 40k Adeptus Astartes Core"," Armors of the lmperium','and ' World Eaters' Mods
from 6.August the bug keep activing

@fox5859 Haar's case will be separately implemented, tho we already have his armor. I'm waiting my Horus Heresy Codex to learn about Royalists' characteristics, including Thousand Sons.

Is there any chance to have a world eater without the nails like Endryyed Harr or any version of preheresy war hounds?

Same as Thousand Sons, Royalist NPCs won't be spawned. I am planning to add separated factions for them later.