What about everything else? passwords, settings . . . . .

Look on your desktop. Do you see a folder called; Old Firefox?

https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible

Type about:profiles<enter> in the address bar. How many profiles are listed? How many should be there?

When Firefox offers to import data from other browsers, that typically indicates that it created a new profile -- along the lines that Fred already mentioned. That may be due to a crash or to a locked file.

If you haven't already, before doing any file moves/deletes/reinstalls, you may want to do a normal system shutdown and startup to release any file locks and complete any pending updates. One user reported it took three shutdown/restarts to sort out his issues.

If your data does not magically reappear, 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?

Unless it was interrupted in progress, you should find a folder on your desktop named Old Firefox Data. Inside would be a semi-randomly-named folder with freshly updated files. Do you see anything like that?

If so, we'll suggest how to rescue key files or completely restore the earlier profile folder.

If not...

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 Folder" button, to launch a new window listing various files and folders in Windows Explorer.

In the Windows Explorer address bar, click the capitalized word Profiles to move up one level in the folder hierarchy. 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 update?

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

There is only one bookmark backup file in the Waterfox > Profiles folder.

There was an automatic update from 54.0.1 to 55.2.0 on October 4th and all the bookmarks were gone.

Hi mschuster, let's continue in your thread here: https://support.mozilla.org/questions/1178301

I've done all that you've suggested that I understand.... I do not have an old firefox data folder prior to the upgrade. There is one now but it has only info from the upgrade forward. It's possible that I deleted the previous folder when cleaning up my desktop as I thought it was from an old computer that I'd moved forward. I didn't realize that firefox did this automatically. I have found the old saved bookmarks but they are in a .jsonlz4 format. I can't load them through the import bookmarks feature in mozilla.

Firefox automatically makes backups of the bookmarks. These are stored in the bookmarkbackups folder.

Open the Bookmarks Manager; Press the Alt or F10 key to bring up the toolbar, and select Bookmarks. Hot key is <Control> (Mac=<Command>) <Shift> B.

Once the window is open, at the top of the page, press the button labeled Import and Backup. Select Restore. From the list, pick the file you want and click it.

The backups are stored in a jsonlz4 file named something like this; bookmarks-2016-06-29_1424_enD1GTH ya0JmicnYWg4V4g==.jsonlz4

In this example; 2016-06-29 = date created, 1424 = number of entries.

Problem solved. I think what I did was to follow the instructions to open the profile folder and then the bookmark backup. From there I pasted the previous backed up bookmarks. I could then retrieve them from the usual method of retrieving them from showing all bookmarks and then they showed up in the restore bookmarks. Interestingly, the old backed up bookmarks do not show up in the "Old Firefox Data" folder on the desktop. I have, however, backed up manually what I have now.

Probably for another thread, but how do I retrieve the previously saved passwords? Same issue, they've all disappeared.

For the passwords you need these two files as a matching pair: logins.json and key3.db

You can copy files like these with Firefox closed to the current profile folder to recover specific data.

• bookmarks and history: places.sqlite
• bookmark backups: compressed .jsonlz4 backups in the bookmarkbackups folder
• cookies.sqlite for the cookies
• formhistory.sqlite for saved form data
• logins.json and key3.db (decryption key) for Passwords saved in the Password Manager
• cert8.db and possibly cert_override.txt for (intermediate) certificates stored in the Certificate Manager
• persdict.dat for words you added to the spelling checker dictionary
• permissions.sqlite for Permissions and possibly content-prefs.sqlite for other Site Preferences
• sessionstore.js for open tabs and pinned tabs

That was very good work. Well done. Please flag your last post as Solved Problem so others will know.

The bookmark backup folder is stored in your profile folder.