Firefox Community Forum

Hello, I am writing to report a critical flaw in the new Firefox Local Backup mechanism (HTML-based container). After formatting my PC and installing a fresh copy of Windows 10/11, I attempted to restore my 10 years of browser history using a valid backup file (.html, ~102 MB) created by Firefox 153.0.4.

Although the password was correct (the UI immediately rejected incorrect ones), the restore process completely failed and entered a destructive loop. Instead of extracting the data, Firefox started infinitely creating hundreds of empty profile folders in %AppData%\Roaming\Mozilla\Firefox\Profiles without throwing a visible error to the user, completely messing up the profiles.ini file.

What had to be done to recover the data: Since standard unarchivers (7-Zip) and tools like Windows certutil couldn’t parse the hybrid HTML/Base64 container, we had to reverse-engineer the recovery process using the internal Firefox source modules (PreferencesBackupResource.sys.mjs and SessionStoreBackupResource.sys.mjs from omni.ja).

We had to write a custom Node.js script to:

1. 1 Parse the specific block-by-block Base64 encoding used by Mozilla inside the HTML wrapper.
2. 2 Manually decrypt the raw binary data using the backup password.
3. 3 Extract places.sqlite, logins.json, key4.db, and sessionstore.jsonlz4 manually.
4. 4 Manually inject these files into a freshly registered profile.

The Bug Core: The built-in extractor in Firefox fails on fresh OS/browser installations due to path/profile synchronization errors, causing a crash loop that generates endless ghost profiles.

Please review the block-by-block extraction logic and add strict exception handling to the Local Backup UI so it doesn't break the profile directory when a routine error occurs.

Thank you.

I was reinstalling my windows and created a backup from my old firefox into my usb drive. My backup failed and coudn't be restored, I'm confident that I use the correct password, tried to copy the file from usb drive into my laptop and select it from there but the result is the same, if you guys would be so kind as to guide me on how to restore my backup, since my password and everything is in there. I didn't create another backup since I believe that this one would succeed. Thank you in advance.e

I got a notice that an upgrade was available. I choose it and it wiped out all my bookmarks, my bookmark bar and all. Nothing works to recover, I tired going to previous version. That did not restore my system. I will quit using your product forever if you do not restore my settings.

So my friend uses firefox (not signed it) & called me over to ask where it's tab groups went. I come over to look & they're just gone. I look to see if I can save new ones, can't, so I update firefox to see if the issue is that perhaps. It brings the ability back, but the previously saved & closed tab groups are still gone. Going to the previous/default(?) profile thing didn't work, so we're not sure what to do. Still looking to see if I can salvage them from history or just find them but Twitter & Tumblr can be hell to look through, especially twitter.

Also I don't know what topic this would fall under, so the topic thingy may be incorrect.

Recently there was a firefox update . When my app was updated I was unable to find my list of bookmarks I had bookmarks for two browsers : safari and firefox. What I find now on my Macmini seems to be a compilation of the two lists of bookmarks

I have no idea how to manage this important issue

Can I recover the last but one version of Firefox and Safari I had before the update, please ?

My Firefox created a new profile and reset everything. I was able to go back and locate my bookmarks and restore them, but my menu bar is reset, my history and saved passwords etc are all gone.

I need my original Firefox account back the way it was. I have no bookmarks, no open page when Firefox opens, and none of my tabs are the same. Please put it back; I don't know how to run my computer this way.

A couple of weeks ago all of my bookmarks disappeared from my profile. The toolbar is empty and when I click manage bookmarks, the entire interface is blank. When I attempt to do the restoration method suggested in the firefox guide, nothing happens when I click the restore button from the drop down. I tried logging out and logging back in, but that didnt help unfortunately. Any suggestions or help is greatly appreciated.

I run normal firefox on linux. Fully up-to-date. Every time I quit the app, it reverts to a version of my profile from a month ago, and loads all the tabs I had open then, and then receives all the tabs that I sent to the device in the interim (~1 month). As I speak, it just caught the 60 or 70 tabs in this window.

I tried changing the name of my profile folder to randomstring.defaultOLD and changed one of the backups to randomstring.default. This didn't change the behavior. I'm still stuck in the loop. I saved my tabs with onetab, because firefox isn't remembering my session anymore. I thought it was something to do with updates, like it only loses its mind upon updates, but that's not true. It thinks it's updating firefox EVERY TIME, because the one time it's loading to 1 month ago it was updating, but I'm 100% sure there are no updates to firefox in my linux. It's just hallucinating.

The articles on restoring from backup are outdated. They say to use an html file. There is no html file. It's just folders for profiles, not html files. HELP!

After the most recent Firefox update all my bookmarks were scrambled. For example, when I open one marked Bank of America, I get Go Daddy. How do I restore my bookmarks to what they were before the update?

I have been using Firefox for years. I am not tech savvy. A very tech savvy member of the family recommended firefox years ago (and now says we should use Brave or another).

Does anyone run Firefox? Why is there no contact centre/people? Why do other members have to answer questions? The reason I am losing total faith in Firefox is that it must made me update and restart and every open window I had (and the tabs on each window) have been lost. I cannot retrieve them, which I have always been able to do via "Restore previous sessions". There was so much important information on those windows and tabs from way back - too far to shift through the history. Can anyone give me one good reason to stay with Firefox? Thankfully, there are many browsers to now use. Firefox has perhaps just become a habit and one I should have changed a long time ago. Thank you.

I moved and when I restarted my computer in the location, I had lost all my bookmarks. The note said foxfire is in use by another application. What other application and why did it destroy my bookmarks?

This is not so much as a help request as a suggestion, if someone can forward this along....

I depend on containers since they were introduced. I see now that they can vanish and are not synced nor can they be easily backed up. I have lost customer accounts now because of my dependence on containers. Had I known they could vanish, I would have continued using different profiles.

Please add a warning for those who depend on containers so that they do not end up in my predicament or remove them entirely or at least do not add them by default.

My bookmarks have not appeared . I have wasted 12 hours x 2 days and followed your instructions . I have not been able to find my bookmarks . I have noticed this is a common and chronic problem with many users . After donating money for years this is very diisappointing.

My Bookmarks (> 100) suddenly became corrupted yesterday while I was browsing. They don't go to anything that they are supposed to. There is no backup profile listed to recover. What do i do short of manually typing in all those bookmarks? Windows 11, No edge but I can use Chrome

Klaud Miller doc@jockdoc.net