Well, apparently I learned that planets can't join fleets to destroy the Dread Lords

I was playing the mission after Achilles Heel (beat that mission with luck, going down to Cakewalk, and giving my money and tech to the allies and let them do the work

) I selected one of my planets to move a ship on it, and the fleet manager showed up, with the planet itself being able to be selected! Wondering what would happen, I selected the planet and a ship and created a fleet....crashing the game.
This just happened, but if it happens again, I will if it happens to just one planet or all of them. Just make sure you don't try to create a fleet with a planet