When I do try to create, rename or delete a profile, I get the message, "An unexpected error has prevented your changes from being saved". I have a new Windows 11 PC. I installed Firefox first from the Windows store and had problems adding a second profile. Now, I've downloaded the full installer and still have the problem after multiple uninstalls, deleting the appdata Firefox folder and re-installing. I've also tried to rename the FF folder after encountering the problem and just restarting FF. It seems to create a new folder with profiles, but I can't create or delete the profiles from the profile manager or from about:profiles. I've also checked that the folders and profiles.ini are not in read-only. I've also tried to manually create profiles or create profiles using the command prompt. Nothing seems to work.