Edit window doesn't show up

Suddenly this week, the editor window does not show up when I double click on the track. Is there a button somewhere that I might have hit that disables this function. Or should I reload the program?

Cubase 7.5

Windows 8.1, i7 chip set, 32 gigs ram, ASUS Maximus VI Hero Motherboard, 260 gig solid state Hard Drive (c:) RME RayDAt interface, Apogee 16x A/D, Big Ben Clock. Mackie Control surface.

solved the problem. It was hidden behind the mix window on my second monitor. It is working now