I just took a turn and received a "Leader Busy" dialog, with options to decline or wait. Choosing "Wait" clears the dialog box but does not clear the Leader Busy state. So I can't move on to things like ships waiting for moves and taking the next turn.
It appears that I'll have to select "Decline" just to get the game to move ahead.
Full Text:
"Raz-Spon Erg would like to trade with you, but is busy trading with the Onyx Hive right now. Would you like to decline the offer, or wait for them to become available?"
Again, I did not ask to trade with anybody in this turn; it just appeared.
Is this a known bug?