When I have a problem, I'm always amazed at how often a simple Internet search will reveal other with the same problem and very often a solution. But sometimes not. The negative results fall into two catgories: either I'm having a genuinely rare difficulty, or I haven't found the right combination of search terms to narrow the results down to something relevant.
I don't know which was the case with our recent Firefox problem, but I couldn't find any help, so I'm posting this in case it might help someone else.
Invisible Firefox, Firefox opens invisbly, invisble window, can't maximize window, perpetually minimized window, can't see open application window. Maybe that's enough search terms, at least for someone who thinks as I do.
You may have guessed the problem. Suddenly Firefox started operating in stealth mode on our laptop. It would appear to be opening, and would show up as a taskbar button, but appeared to be perpetually minimized. But in reality it was maximized ("maximize" was greyed out when I right-clicked) but invisible.
I won't detail everything I tried, but it was an interesting puzzle and I did find some interesting things, including that the program was still running and would respond to keyboard controls, even though I couldn't see what I was doing. That way I was able to bring up the bookmarks manager and export the bookmarks, which provided a measure of relief.
Doing a system restore did not work; the process was unable to complete for any of the three restore points I tried.
I uninstalled and reinstalled Firefox, but even that was not enough.
After I discovered that uninstall doesn't delete your profile, I repeated the uninstall, then changed the names of the old files to force the reinstall to create a new profile, and that did the trick: the Firefox window was visible once more.
Clearly something about the profile had become corrupted, because when I switched back to the old profile (by modifying the profiles.ini file), the problem returned. I had planned to add pieces of the old profile back in a bit at a time to try to discover the source of the problem, but then decided I didn't want to spend any more time on the project; it was faster and easier just to import the old bookmarks into the new profile, set up our customizations again, and deal with the loss of a few cookies and remembered passwords
If this story has a moral, it is the same moral as in all computing tales: backup, backup, backup.
