I know a lot of people are having trouble with looting the disguise out of the merchants chest for "A Hostile Situation". You most likely are receiving the message "you already have this item" or "You can only have one of this unique item in your inventory". The good thing is you do indeed have it, but it got sent to your bank I have confirmed this with two other players. Now you cant get to the bank in that area due to the quest so you'll have to run to Khenarthi's Roost or another bank to get it. hope this helps