I'm having issues with a sorceress that has "completed" the act 4 quest to kill Diablo, but can't get Tyrael to open the red portal. If the red portal is open, she can't go through it.
If she starts a new game, the Diablo quest is shown as completed in her quest dialog.
If she joins a game in which the quest has not been completed, and kills Diablo, her quest shows as "you cannot complete this quest in this game". Other players in the game have the quest complete correctly.
The bug happened when I entered a Diablo game that was very close to finishing. I requested to be added to the party, but was not. I had my quest dialog open and the Diablo quest selected when the players in the game killed Diabo, and it displayed the quest-completed animation when Diablo died, but wouldn't let me enter the red portal.
Is there any way to fix this character, or do I have to throw her away and start over?