ExpandedTerraria banner warnings spam, KeyNotFoundException in a Calamity IL hook during item name formatting, interacting with InnoVault and FargowiltasSouls and then surfacing in YAQOLM UI. That’s a three-way hook chain
Imo and without knowing which mod exactly is interfering with abyss generation, what you should do is
Install tmodloader from steam
Generate the world only with calamity + requirements, that way it should succeed. Then add the mods back in small batches to find the culprit mod that interferes. My guess would be remnants because I've heard that it's notoriously incompatible with Calamity generation of the oceans