Window appears off screen on ubuntu

You can get the window back on your screen by using

ALT + spacebar

This would show you the maximize/minimize/ ... options. Click maximize and it would occupy your screen.

You can also hit "move" and then either your mouse or arrow keys to move the window to your current window.

I made a little script to fix a similiar bug I have in ubuntu 15.04 with two screens: https://github.com/mezga0153/offscreen-window-restore

The script makes use of the wmctrl command line tool to find the offscreen windows and then uses wmctrl to place each one back into a visible area.

Be sure to have the off-screen window selected (use Alt-Tab or Super-W for example). Then hold Alt+F7 and move the window with the cursor keys until it appears in the viewport.

When this happens to me the hidden window is usually below the screen (I occasionally use two screens with one on top of the other, a setup that agrees well with a laptop on a desk). If you use Super-W to select the window, you can guess where it is by looking at the animations. Holding Alt+F7+Up brings the window into view for me.

Cheers.