I had this problem as well and I had installed all mods (correctly
) before starting a new game, so I don't think that is your problem. The mods I used that you used as well were virtue, unfinished business dungeon be gone, gibberlings, and item upgrade. I assumed it was because of the unfinished business mod with Minsc's quest, but that was just because it was Minsc and no one else. Try uninstalling that section of unfinished business to test. I eventually had to just get rid of Minsc because it was so frustrating, but on the bright side, no one else did it.