Hi 2006hazelmurray, make sure you don't use a space in about: addresses. Otherwise, Firefox probably will run a search instead of loading the internal page. So please try:

about:profiles

That said, if your data was destroyed by Sync, you might need to use a Time Machine backup. But we can come back to that if necessary.

Before that, try using any available automatic Firefox bookmark backups. This article has more info on those: Restore bookmarks from backup or move them to another computer.

I figured that out & got to it. Using the process in that article you cited & others on the support website, when I tried to pull up the old profile, it didn't show. But whenever I go to finder outside the prompts & windows conjured by the processes in the support articles, the finder clearly contains right at the top: Firefox Profile in a blue folder. When I guess at what might be the old profile among the folders that do show during the processes decreed in the article, and try to restore, the open option (or whatever it is that isn't "cancel") is greyed out & all I can do is cancel. I'm sorry I can't remember all the excruciatingly detailed instructions, which I copied & put in a doc for when I had to close out firefox & work outside the browser. But when I opened firefox again, it had deleted all my add-ons. I put em back. tried again. ate a half a box of candy. did other stuff. took my pills. tried again. now replying to you & the rest of the support group in hopes you can enlighten me. You're very kind to help me. I hope I can figure out what the Time Machine is & where, if I need it now. Thanks for responding & helping. Hopefully you'll stick with me.

This is the exact process I used:

"Restoring from backups

   Click the Library button on your toolbar. ( If you don't see it there, click the menu button. ...
   In the Library window, click the. Import and Backup button and then select Restore.
   Select the backup from which you want to restore: ...
   After choosing a backup, your bookmarks from that file will be restored.

Restore bookmarks from backup or move them to another ... support.mozilla.org › en-US › restore-bookmarks-from.."

and when the finder appeared with the desired "Firefox Profile" file/folder, and I highlighted it, the "open" option stayed greyed out.  I had no way forward.  I added this for clarification of my previous, unclear explanations.

Hi 2006hazelmurray, I'm missing some of the steps there.

Profile Manager

Did the about:profiles page list any additional profiles?

Usually the one you're currently using will have this:

This is the profile in use and it cannot be deleted.

Were there any others listed? If so, you could check whether it has valuable data in it by clicking its Launch profile in new browser button.

If it isn't what you want, simply close that new window.

If it IS what you want, we can discuss option for how best to use its data.

Finder

You said:

But whenever I go to finder outside the prompts & windows conjured by the processes in the support articles, the finder clearly contains right at the top: Firefox Profile in a blue folder.

I don't know Finder very well, so I don't know what is in that blue folder. Did you double-click into it to see whether it is what you already know about or something new?

Restoring a Bookmark Backup

I gather the Restore menu only had the Choose File... option and didn't list any older backups? Using Choose File... you want to find a file whose name is similar to:

bookmarks-2020-06-05_1575_gibberish==.jsonlz4

In other words, it will have a recent date in it. And it should be in a subfolder named bookmarkbackups in one of your profile folders.

Thre are two other profiles, with that button that says "launch in new browser". I tried that but a message told me that it's not possible to launch two mozilla browsers at the same time. And there's no way I can see to get to that "launch in new browser" button without already having firefox open. Which makes it impossible to launch the profile in new browser.

As for the restore option, it has only "Choose file" option after "Restore". Directly beneath but not an option under "Restore", are two other phrases: "Import bookmarks from html" and "Export Bookmarks from html". When I choose the first, "Import," the finder appears and I can click on "desktop", where "Firefox Profile" plus ",,," and some numbers appear after I highlight it. The option at bottom is "cancel". "Open" is greyed out.

I thought my old bookmarks might be in a little device--a "thumb drive", maybe?-- that I think was used to transfer data from my mac mini to a chromebook. I took it out of the Chromebook and stuck it into the mac mini port, but nothing happened. So I guess I could try to go into the Chromebook and get the bookmarks, since it was busily transferring all my mac mini files to the chromebook till I accidentally stopped the whole process in the middle of it. But it should have the bookmarks. I have so little tech savvy that that prospect staggers me.

Back on topic. I did double click on the blue folder and it has a "bookmarksbackup" file from May 26th. I don't know how to transfer that file or the rest of the files in the Firefox Profile file back onto this version of firefox that I'm using. The one that wiped out my add-ons and home page. Twice so far. Seems to do it every I close firefox and re-open it.

I must be really close to solving this, since I found the "bookmarksbackup" folder, and the profiles, including the one that can't be deleted, right? Ok, I'm eager to hear how to utilize the folders, the profiles.

Hi 2006hazelmurray, if you found additional profiles on the about:profiles, did using Launch profile in new browser for any of those additional profiles give you a window with the data you wanted?

As I noted, trying to launch the Profile in a new browser triggered a message that it is impossible to open two Firefox browser at once. Since I was already in Firefox, it didn't allow me to do that. It might work if I did it from Safari. I'll try that next. thanks for answering. Carol

Wait, I think I can access that page only from being firefox. I'll see.