. What happened to Mozilla Firefox? It no longer works. I had it as my default but had to switch over to Edge to get to Facebook, Gmail, , etc. Restarted computer twice, and it still didn't work. Clue (?): The desktop comes up as usual. Used shortcut to try get to Facebook. First time a message from Mozilla flashed on the screen about something to do with PDF, but not long enough for me to read. After that, only a blank screen appeared, the little thingy that goes back & forth in the tab showing the program was in the midst of getting the website I wanted was not moving, which I think means something was stuck I am not very computer literate.