My OS has developed a fault where some windows open top left so the title bar with the min, max and close buttons are just off screen. It doesn't happen with every program.
Firefox, gedit, Tuxguitar and the Onboard keyboard preference window seem to be the main culprits.
LibreOffice, Transmission, Quod Libet are OK.
Why does it do this?
Is there a fix?
Terry
Even though it was posted 2012, it works for the "bug" that showed up running 16.04 when nothing else worked.
https://ubuntuforums.org/showthread.php?t=1967258
In short, download CCSM, click on Windows placement, select Smart.
Ok found answer to 2, just recreate a new user as the problem seemed to be corrupted user settings.
Not sure on 1 but I think it might have been because bleachbit was set to delete user settings. Don't want to check this by experimenting on a working system right now.