"The Will of Ashan" - "Heart of Darkness" [2nd campaign, 5th mission]

Oh my god, something terrible happened -_-.... I completed the entire map in the "Heart of Darkness" act, earned a lot, defeated everyone, collected all the artifacts... and then, when I was heading to the Sanctuary... I forgot what was there... a magical barrier appears, and the ghost of the killed Knight appears and asks me to help him... the hero agrees... and... that's it (the mouse is in the loading mode, I can't do anything... and I saved the game like an idiot:(
Guys, please help me because I spent 2 days on this act:(