Upon the clean, newly downloaded from Mozilla copy of Firefox for Mac, I will get a pop-up window asking, "Open existing Firefox application?." What is obviously spurious about this window is that there is only one copy of Firefox installed. I have used the recommendation by someone on the Interwebs telling me to go to the Terminal App and execute: /Applications/Firefox.app/Contents/MacOS/firefox -bin -P ..after which a small applet window (called "Firefox - Choose User Profiles") pops up where I see the installed profiles for Firefox. I was told to delete all but one of the profiles, check the "Use the selected profile without asking at startup Check box, and then hit the "Start Firefox" button. Firefox then opens up. If I quit Firefox and fire it back up again, I again see the little, "Open existing Firefox Application?" window. This goes on forever. I have also given Firefox Accessibility, Full Disk Access, and Screen Recording rights, but to no avail. Any ideas?