Having this same problem today as well. Entered into Brayflox's dungeon and exited out because one of our party members had to leave. Regrouped and tried to re-enter with Duty Finder. When we did it one of the members DC'd and we got the message that one person didn't accept the command. Got a replacement and everyone withdrew and tried again. Got the message "You are unable to accept a new duty. Please try again later." Logged out and frustratedly got back in game. It worked again but it didn't show up on one person's window so we went back to square one when having to withdraw once again. ><;