2 major bugs are preventing me from playing the game properly

[Xelag]

Hello,
I have 2 major bugs on my Marksman character (Xelina):

1. I can’t teleport to Lightless Arbor waypoint, the game ALWAYS hangs on the loading screen (waited 10+ minutes many times - nothing happened, the game is frozen). Same problem when I try to enter Soulfire Bastion dungeon zone (zone where the key has to be inserted to open the dungeon) - freeze on the loading screen. Temporal Sanctum works.
2. I played the campaign quite chaotically with friends, e.g. I played Act 1 after completing Act 6. Now I stuck with the quest “Liath and Thetima”, with the part “Speak with Yulia in Thetima” - she is just not there, so I can’t speak with her at all. And there is a problem in Deep Harbor - if I speak with Harbard the Ferryman to head west and click on “I’m ready” - nothing happens, I am not being moved to another city.
   Both problems are extremely annoying and prevent me from playing the game on my main character. Please help.

[Xelag]

I found Yulia in Thetima (without the usual golden sign as it’s not shown), BUT she is trying to send me to Maj’elka as if I’d have fought Lagon already, which is not the case… And if I click in the dialog on “I’m ready” - nothing happens. There must be some weird hickup with the campaign now.
Also important to mention that my friend opened me waypoints to all major cities in the game, maybe this has somehow screwed my campaign and even the dungeons?

[Xelag]

I reinstalled the game completely and now I can again access the dungeons. But the campaign problem is unsolved.