Silhouette of full screen app using mission control stuck on screen I was trying to move a full screen app from my external monitor to the macbook screen after activating mission control by dragging and dropping. The app was not moved across screen. Instead only a silhouette was caught on the macbook screen. I managed to move the full screen app over after a second trial but the silouette from mission control is stuck on the macbook screen and blocking the top left part of the screen. 

Please see the attached screenshot fyi.

How do I get rid of the silhouette?
Mission Control is part of the Dock process. Restart the Dock to fix it.

killall Dock