Trade Counteroffer Bug
When I offer a counter to a trade, it shows up in my opponent's trade box as an acceptance. He cannot see the counter offer, he just sees a check mark for an acceptance. When he accepts, it enforces the counteroffer, not the original trade. So he accepts a trade that he was not expecting. This bug is new as of tonight, as far as we know. Our computers all updated Catan with the tournament mode right before we played.