When a user drags a GTK window past desktop bounds, in some cases they may be unable to
be able to re-move said window back into bounds as there is no way to easily "grab" the
Window and move it into the correct location. A simple workaround is to right-click on
the window entry on the bottom mate panel and select the "move" entry manually.

Video of the problem:
[https://vid.me/mZhn]