Hi Mac73, if you click into the Old Firefox Data folder, and then into the semi-randomly-named profile folder, and look in any bookmarkbackups folder you find, are there files in there from before the problem began? (Each file has the date and number of items coded into the file name.)

If you find a file that seems right, you can use the Restore feature to apply it to your current Firefox profile. See: Restore bookmarks from backup or move them to another computer.

If not... the most likely scenarios for complete data loss are:

(1) A Refresh started but the migration of data from your old profile to your new profile was incomplete, or
(2) Your old profile was locked, so Firefox ignored it and created a new one.

Here's how to investigate those two possibilities:

Did Firefox perform a Refresh?

You've already found the Old Firefox Data folder. Does it contain files from before the data loss, or only afterwards?

If those are not old enough...

Does the Profile Manager list your immediately previous profile folder?

To check on that, inside Firefox, type or paste about:profiles in the address bar and press Enter/Return to load it.

This page should list all the profiles Firefox is currently aware of. If you see a profile that is not currently set as default that looks promising, scroll down to it and click the Set as default profile button below that profile, then scroll back up and click the Restart normally button. (There are some other buttons, but I think those are still "under construction" so please ignore them.)

Firefox should exit and then start up using the other profile. Is that the right one?

If it's not there...

Did Firefox orphan your old profile folder?

Here's how to check whether there are additional profile folders in the standard location in addition to the one you're using. Start by opening your current Firefox profile folder using either:

* "3-bar" menu button > "?" button > Troubleshooting Information
* (menu bar) Help > Troubleshooting Information
* type or paste about:support in the address bar and press Enter/Return

In the first table on the page, click the "Open in Finder" button, to launch a new window listing various files and folders in Finder.

You want to view the folder named Profiles, which is up or left from the current live profile folder. More than one folder here by any chance? Do the files in those folders look like they were last updated around the time of the problem?

If you've got any promising looking folders, we can discuss next steps to recover use of them.

Here is what happen. Yesterday I purchased ScanGuard for virus protection and after scanning, it did a System Boost. There were some files with a circle and a slash through it that I said to delete. After all that, my Firefox was gone. So I downloaded Firefox again. When that came up, my bookmarks, passwords and etc. were all gone. I have a LaCie backup hard drive where I drug a old copy of Firefox (a week older saved backup file) from it onto my desk top. After placing it in the Applications file and restarting still no bookmarks. I have again went to the LaCie and from a Sept. file I copied the default profile file and pasted it in my profile folder. It asked if I wanted to replace it with an older file. Still nothing. So I am lost and in panic city for all the bookmarks I have lost!!

Okay, Firefox is expecting a specific semi-random folder name and doesn't "see" the old one. You can fool Firefox by changing the name of the old folder (the one you copied into the Profiles folder from your backup) to the one it is looking for (the name of the live profile folder). Two folders can't have the same name at the same time in the same place, so you may need to (A) Quit Firefox, then (B) move that new profile folder somewhere else (e.g., your desktop). Don't delete it right away because we need easy access to its name, either for copy/paste or to be typed manually. Can you make the switch?

Or actually, it might be safer JUST to do the bookmark restore. Copy the latest backup from the old profile folder to your desktop. Then on the Restore menu mentioned in the article I linked before, click Choose File, and point Firefox up to the desktop to restore that backup.

I have done the Restore from the one help site for Firefox. I have a different file name in that file created when I clicked on the site's restore button. So I need to open the profile folder, click restore and then have it go to the "Old Firefox Data" folder and have it use the default file there?

The Restore feature for bookmarks is not something you do through a website. Please check this article again: Restore bookmarks from backup or move them to another computer. The Restore menu has "Choose File" and that's how you point Firefox to the backup you want to restore. It could be in your Old Firefox Data or it could be in the folder you copied over from your backup disk.

Here is where I went: https://support.mozilla.org/en-US/kb/refresh-firefox-reset-add-ons-and-settings?redirectlocale=en-US&redirectslug=reset-firefox-easily-fix-most-problems and it has in step one a Restore button that I used. This is where the Old file can into play. So i use a file from the Time Machine or is it hooked up to my LaCie?

Sorry, I can only view the page in English, and there is no Restore button. There is a Refresh button, which will most definitely NOT help you get your data back. As you already know.

Please refer to the article I provided the link for.