I couldn't complete the first mission because Hangwul decided to stand in the garrison, and after that, my turn wasn't passed to me.
Do you have any saves from before that point? Did loading a save and changing the main character's turn help?
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I started playing the updated version of the campaign and noticed something; I don't know if it's a bug or not. I captured the first Dwarven Castle, Khrottar, and for some reason, none of my heroes interact with it. I can build in it, I can hire heroes in it, but it's as if I can enter the castle, but the heroes aren't displayed in it. It's strange, and as a result, I can't learn spells in it because of this. Has anyone else encountered this? Is it a bug or a feature (no third-party mods, just a clean 3.1 version)? I can enter the city using the "Portal to City" spell; heroes are not displayed in it using the normal method.
This was definitely not intended... Do you have a save file where I can take a look?