Hello. I've been using Firefox 81.0 with MacOS 15.7. I opened FireFox recently and after a few moments it froze, so I had to force quit. When I tried to open it again, it told me that 'A copy of Firefox is already open. Only one copy of Firefox can be open at a time.' However, I only have one copy open, or anywhere else on my HD. When I click "Okay" to close the prompt, Firefox freezes again and I have to force quit. I tried deleting the application using my existing Profiles folder. Again, it froze. I deleted the app and the Profiles folder, used Safari to download a fresh version of Firefox 81.0, installed it, and it ran for about a minute before freezing. Again, I had to force quit. And again, when I reopen it, the same prompt: 'A copy of Firefox is already open.....' I Firefox froze when I tried to close the prompt. I can't even reinstall a fresh version of FireFox. I don't know what to do. I'd greatly appreciate any help. Thanks.