When using openSUSE and opening Firefox the screen remains blank while the opened application appears to be off-screen. How can we cause the opened applications to open on-screen? --It is not only Firefox, but not all applications either.
Some applications, such as Firefox, remember where they were last opened, and if at that time you had 2 displays, that might explain your experience. Go to the icon bar (usually at the bottom of the screen, right click on the application icon, and select "Move". That should let you move the window for the application to your current display.
Another possibility is that you opened it in another workspace (virtual displays). The thumbnails for those should be at the right side of your bottom panel where the application icons appear. You should see a representation of the application window there if that is what happened.
Thanks for your reply. Yes at one time I did try to connect 2 displays; However, that didnot work. So I moved on and forgot about it. I am able to open applications by typing in the box that opens when I press alt+F2. I have no icon bar although at one time I did. So I do not see the Firefox icon or any other icons. And yes there was a time when I was able to somehow move Firefox from the off screen right hand side of the screen to the middle and then use it. That is not the case now. Searching for clues to my challenge have not been helpfull so I do appreciate your ideas. I can use Chromium just fine.