Closed location interferes with passage (Torchlight 3)

Hey. In one of the last tasks in the game, when you need to go to the King's Plateau, the path to it is blocked by a large structure that cannot be bypassed. In the only one found my passage, the other player does not have this - the path is free there, plus two intermediate bosses appear in the location, which I do not have at all.
Perhaps someone has come across a similar one and knows how to solve it? Maybe I didn't complete something in the plot? There are no open tasks, I talked to all the characters. There are two locations left before the final ((