Encountered a game breaking bug

[Sidor14]

I am fighting the final boss of Shadows of Undrentide, and I have crushed all of the Mythallar containers, and still Heurodis is invicible to any damage type. Any ways to fix it?

[soltan-heatwave]

I have had that happen a few times, even in the original game. If you get that the only thing I can suggest is to exit the game, restart it, and load a save prior to the final battle.