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firefox updated itself and deleted all of my passwords, history, and bookmarks without my permisssion.

  • 11 replies
  • 1 has this problem
  • Last reply by jscher2000

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subject line says it all..although i can add the "old firefox data" folder on my desktop contains a blank default profile from 2017.

btw, this is exactly the kind of thing that makes my company drop software.

All Replies (11)

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To restore this data:

On the desktop you should see a folder called 'Old Firefox Data' open it and copy all the data by highlighting and selecting everything in that folder, then right click and select copy. Now open FIrefox. Head on over to about:profiles by typing it in your URL bar. Click on the Open Folder button under the Local Directory, not root. Then right click when inside the new profile folder and select paste. Then restart Firefox. You should now have all your previous bookmarks, and data back.

If this solved your problem, mark as solution.

thank you


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When you are ready, we can start moving parts of your old data and Copy it to the new profile.

First; open your file browser to the New profile;

Type about:support<enter> in the address bar.

Under the page logo on the left side, you will see Application Basics. Under this find Profile Folder. To its right press the button Show Folder. This will open your file browser to the current Firefox profile. Now Close Firefox.

Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder

Linux: Under the page logo on the left side, you will see Application Basics. Under this find Profile Directory. To its right press the button Open Directory.

Second, open another file browser to the Old Firefox folder on your desktop. Then open the folder with the latest date, or whatever one you want to use.

Warning ! ! Only Copy the files you are told. We will avoid anything that might cause problems.
Here is the list of files;

cookies: cookies.sqlite Do not bother. Cookies will be created when you return to the website. However, you will have to log in everywhere. And you may lose any settings that websites store on your computer.

extensions(add-ons, themes): it would be better to download them fresh. If you need to remember what add-ons you had, open the extensions sub-folder and look at the .xpi files

logins.json and key3.db [v58+]key4.db : These are the password files. Copy Both !

persdict.dat : custom dictionary - words you added to the dictionary

mimeTypes.rdf [v55+]handlers.json : What to do with what type of file.

places.sqlite : History and Bookmarks.

prefs.js : Your settings. Note: If you were having problems, this could be contaminated.

cert8.db [v58+]cert9.db and possibly cert_override.txt : Stores all your security certificate settings and any SSL certificates you have imported into Firefox. If removed, the cert8.db, cert9.db file will be replaced.

search.json.mozlz4 : file stores the user-installed search engines that are available in the Firefox v47+

search.sqlite file and searchplugins folder store the search engines that are available in the Firefox Search bar before Firefox v47

Copy these files from the old to the new. You may get a message that the files already exist. Choose to
over-write for each file.


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Is there only one profile present on the about:profiles page?


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the "old data" folder on my desktop is identical to the new default profile.

when "logging in" after the update, firefox would not accept my password immediately.

i loved this opportunity to log into stuff and chat with people, but i have work to do. i understand it is unrealistic to expect things to continue to work every day.


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ZAPEEE265 said

the "old data" folder on my desktop is identical to the new default profile.

Is there another folder created about the same time?


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why do you people keep telling me to copy the "old data folder" from my desktop when i am telling you it is a duplicate empty default folder.... do you read these things or just paste in an answer.



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Hi ZAPEEE265, the Old Firefox Data folder is only relevant in the scenario where Firefox performed a Refresh, so now that you've ruled that out, let's move on to the other suggestion made earlier in this thread.

Did you try checking the About Profiles page? That is:

Profile Manager Page

Inside Firefox, type or paste about:profiles in the address bar and press Enter/Return to load it.

This page should list at least one profile and could list many. (Each profile has two folders and one or more buttons. Do not use any Remove buttons!)

The profile that Firefox is currently using will have this:

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

Do you have another profile named default or default-release or default-longnumber listed on this page? If so, you can check whether it is the one you were using recently 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, back on the about:profiles page, click the Set as default profile button for that profile so Firefox uses it automatically at the next startup.

Any progress so far?


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there are two profiles, a new empty default folder and a duplicate on the desktop called "old firefox data"


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The folder on the desktop should not be listed on the about:profiles page. So just to confirm, you only have one profile listed on the about:profiles page?


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today there are three

default default-release default-release-1

trying to activate default gives "old version can corrupt" error- creating new profile & opening gives profile without bookmarks default-release is basically empty with 3 bookmarks i created yesterday default-release-1 seems identical to default-release


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Could you check for files: Go to the table below Profile: default and use the "Open Folder" button for the Root Directory. This should open that profile folder in Windows Explorer. Double-click into the bookmarkbackups folder.

Are there any recent backups here? The date-time is coded into the file name, for example:



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