Firefox window is hidden if Displays have separate Spaces
A few weeks ago my Firefox browser window disappeared. Right clicking on the Firefox icon on the Dock (Mac OS Sierra) and selecting 'Show All Windows' showed my Firefox browser window in a kind of preview mode on one of my three monitors - but there was no way I could figure to get the window to show normally.
No way at least until I figured out this workaround > Mission Control > turn off ‘Displays have separate Spaces’.
Problem is I have not been happy these past few weeks with this workaround - I 'do' want to have separate Spaces for my monitors (this is the only thing I use Mission Control for).
Any wise souls got a solution?