I may have isolated one of the causes of CTD. Three times in my recent game, a "powerful enemy" was spawned from an explored lair. Once, it was my explore, and twice, my closest neighbor, Decius of the Malakim. All 3 times, when the "enemy" won a battle, I would get a CTD. Pretty sure that all three were Bhall's units - (1) axeman with orcish, woodsman 1+2, combat 1+2, (2) axeman with orcish, woodsman 1, combat 1+2, command 1, (3) ogre with combat 1+2 (possibly other promotions, not sure). I've noticed similar stretches of CTD shortly after having seen the message that Orthus has been created.
When checking with WB, it seems that the units were gaining enough XP to level. I suspect the CTD is somehow related to the leveling, perhaps due to the preexisting promotions. Since all the units I saw were combat 2, and the AI usually promotes in line, perhaps it's specific to taking combat 3? On the other hand, I've definitely seen a late game combat 5 Orthus (as an aside, giving Orthus the hero promotion is just mean).
Deleting the units in WB, changing tactics so the "enemy" died on my turn, or adding a mind 3 unit to dominate the "enemy" all prevented the CTD.
When checking with WB, it seems that the units were gaining enough XP to level. I suspect the CTD is somehow related to the leveling, perhaps due to the preexisting promotions. Since all the units I saw were combat 2, and the AI usually promotes in line, perhaps it's specific to taking combat 3? On the other hand, I've definitely seen a late game combat 5 Orthus (as an aside, giving Orthus the hero promotion is just mean).
Deleting the units in WB, changing tactics so the "enemy" died on my turn, or adding a mind 3 unit to dominate the "enemy" all prevented the CTD.