A THREAD FOR NEWCOMERS!

Hello! I'm playing the "The Fallen Empire" campaign, map 6. The following situation occurs: when the dungeon is opened, the message "The Jailer informs you that the prisoner who was held in this dungeon has been released by order of the king who imprisoned him" appears, the dungeon disappears, but the hero does not appear in its place. What could be causing this, and is it possible to fix it, because a hero is supposed to appear there, and he is needed for the next part of the story, and the campaign gets stuck without him. I'm attaching a save file, the version is Heroes Complete Collection with an HD mod.