Hi, your Firefox identified itself to the forum as version 72.0.2 running on Windows 10. That version was from about a year ago, so I'm not sure you actually updated. More like downgraded? If an older version of Firefox replaces a newer one, Firefox usually will display a message that it can't use your saved settings and needs to create a new profile. Do you recall seeing anything like that right before the problem started? If you didn't see any message like that, it might indicate you have both an old and a new version installed. Let's research this a bit more before taking any drastic action. '''Check compatibility.ini files''' First, please set Windows to show hidden files and folders: https://support.microsoft.com/en-us/windows/show-hidden-files-0320fe58-0117-fd59-6851-9b7f9840fdb2 Next, in the Windows 10 system search box, paste this shortcut path and press Enter to launch this folder in Windows' File Explorer: %APPDATA%\Mozilla\Firefox\Profiles The Profiles folder may contain one or more individual folders with odd names -- the left part is random letters and numbers, then there is a dot, then the right part is text like default or default-release. How many folders do you have here? Each individual profile folder should contain a file named '''compatibility.ini''' that has information on the last version of Firefox that used that folder. This is helpful to figure out whether your Firefox downgraded somehow. Note that by default, Windows hides the .ini file extension. You can set Windows to show all file extensions while trying to spot specific files: https://www.bleepingcomputer.com/tutorials/how-to-show-file-extensions-in-windows/ Usually a .ini file will open in Notepad if you double-click it, and the contents look like this: [Compatibility] LastVersion=84.0.2_20210105180113/20210105180113 LastOSABI=WINNT_x86_64-msvc LastPlatformDir=C:\Program Files\Mozilla Firefox LastAppDir=C:\Program Files\Mozilla Firefox\browser Can you look at your compatibility.ini files and see what they tell you about the version and the installation location? On 64-bit Windows, you might have Firefox in either of these paths, and a dual install, could cause problems: * C:\Program Files\Mozilla Firefox * C:\Program Files (x86)\Mozilla Firefox What did you find?