This may sound like a simple off screen issue, but it seems to be worse. I have a Retina MacBook Pro 15" that I dock, closed, to a 30" and 20" displays. One day after undocking, a 3D modeling program called Hexagon that was open, vanished, yet it was still open. I've tried moving the screen arrangements of the external displays to find it off screen, adjusting resolution, gather windows option, move the application to certain desktop space, and other tricks, just doesn't seem to help. (I have 4 desktop spaces set with dual screens) When the software launches, I see a small window on the top left that disappears instantly. The software has no options at the top of the screen, they are all part of the application window. If I try command-o for open, the program instantly crashes. If I use its uninstaller, then reinstall, when it asks for the serial, that window's center is stuck at the top left corner of the screen, so only a quarter of it is visible. I tried lowering the resolution until I could grab the top of this window and center it, but the program was still gone after. Is there an OSX settings history for applications regarding their position and size that can be deleted? It's almost like the program is stuck in an impossible placed or shrunk to a pixel and gone. I guess I'll try a 3rd part program for window management to see if that helps, but I doubt it. I'd hate to have to reinstall OSX just for this program. I'm using Modo these days, but Hexagon comes in handy now and then.