Cannot cancel order to drop troops

Description

I atacked with a transport full of troops the enemy planet. There was no population on the planet, but just some remaining facilities and guarging fighters.

When i gave the order to drop troop on the planet the game told that he cant drop troops because tehre no population on the planet, but the drop troops order remained.

I could not click the planet to select it and see what's on it because the game was still expecting input on where to drop troops....