I wanted to check if succubi have been added to the Inferno towers during a siege. I launched a mission for Agrael, where the elves in his army desert, and attacked a demon city. The mod version is 17.09.02-Beta, installed on 3.1, with your mod applied to all heroes.
Added 15 minutes later
In the finale of the fourth mission for Zehir, before the ritual over Isabel, another cutscene should have played, where Railag at the ruins of the Claw confesses to Isabel that he is Agrael.
Yes, I brought the Succubi back to the towers. I confirm the crash in this mission; I should have blocked the campaigns for the time being in this update, as they seem to have become very unstable.
In the next update, only the missions for Isabel will be available until I return to the campaigns.