Repeated crashes after restoring save games at high DL
Game crashes several turns after restoring saved game on high DL (lets say, DL:30) with "Invalid monster type created: #430". You need to kill several monster before saving, so you trigger monster respawn on current level.
Switching the level solves issue until next restart.
Possible cause - initial seeding of monster rarity table on loading does not take in the account modified rarity from DL of the current dungeon, leading in larger table that it actually is and out-of-bounds monster generation due to that.