Hi, that folder is created when Firefox performs a Refresh. It contains the old profile folder Firefox was using at the moment of the Refresh.

A Refresh should carry over your bookmarks, history, and logins, and should clear custom settings and add-ons. Does that sound like something which happened around November 1st on your Firefox?

If you haven't been desperately searching for old Firefox data, then I don't think you need the Old Firefox Data folder any more. If there is anything you want might to rescue from that folder, could you mention what it is?

I HAVE NOT HAD ANY PROBLEMS SINCE THE UPDATE ON 1/1/20, HOWEVER, I HAVE ABSOLUTELY NO IDEA WHICH [IF ANY] OF THE 1700-1900 FILES W/IN THE Old Firefox Data FOLDER I FOUND ON MY DESKTOP I MAY OR WILL NEED... SO TO ERR ON THE SIDE OF 'CAUTION' I'LL JUST HANG ON TO THE FRIGGING FOLDER A BIT LONGER. THANK YOU FOR YOUR RAPID AND HELPFUL REPLY. xxxxxxxxxxxxxxx@xxxxx.xxx xx xxxx

(email address removed by moderator; please do not post personal information on a public website; Forum rules and guidelines)

What is the name of your current profile folder?

If you create a new profile due to a refresh then this is normally a profile name that has a timestamp appended to the name.

You can also check compatibility.ini with a text editor to see what Firefox version last this profile.