unity3d - unity 5, how to open saved scene? -

when start new unity 5 2d game. default, has scene, game , asset store tabs. saved scene , named movementstaging, closed scene tab. cannot open again. right click on it, , choose open. nothing happens. how can scene tab back?

right click on tab ->add tab -> scene. double clicking on saved scen should open in scene tab. restarting unity helps of times. can try window -> layouts -> default