This is according to the screenshot a coalition event. I had that once too, the cause was that I left my coalition during this kind of tournament, which blocked access to the reward. So to make this tournament disappear from the list, you can contact the help desk to unlock this, but I doubt that you are taking the rewards unfortunately ...
Otherwise wait a few weeks, this "half bug" will disappear.

All this of course if you left your coalition during this tournament.

PS: it's an assumption from my experience