I keep getting this pop-up that says "Facebook Password: Enter the password for "email@example.com" in System Preferences". When I go to preferences it says there is an issue with system preferences and I can't get out of the pop-up or into my preferences. My Mac is a 2011 and completely up to date with no malware or anything. I think I may have deleted something I need for it but I'm not sure what has happened. Does anyone know what to do or how to fix this?