Diễn đàn hỗ trợ Firefox

Mozilla, in their infinite wisdom, sent me a note about something new in firefox, by displaying it in a new instance of Firefox.

It wasn’t until I closed my normal session, that I realised a new instance of firefox was also running, and shut it down on.

In shutting the new instance down after my usual session, it overwrote all my normal tab settings🤬

Q1. Are my normal tab settings recoverable? Q2. Why did Mozilla think it a good idea to open a new instance of Firefox to send me information, rather than simply open a new tab.

NB This is in Windows 11

My laptop unexpectedly closed Firefox after it crashed and upon a restart I re-opened Firefox, which normally restores all my open windows/tabs from the very last session no problem whenever it force quits due to laptop crashes. But this time when opening, it restored windows/tabs from almost a month ago. I closed Firefox and checked the sessionstore-backups folder: - the recovery-backup files are from the session date I just re-opened with old tabs - the previous.jsonlz4 file is from about a month ago and seems to be the reference point used when restoring tabs rather than my actual last session

Is there any other file or method I could use to recover my actual prior session tabs before it crashed?

I have not re-opened Firefox since quitting the browser after seeing it restored the old tabs.

Thank you in advance!

Hello, I have just installed Firefox version 144.0.2 on a new computer. I have access to all of the Firefox files and data on the original computer, but I am not able to run Firefox on that computer. Therefore, I am not able to create an export file from the original installation. Is it possible for me to import all of the original Firefox data into the new installation? Thank you very much in advance, Steve DeFeo

I rebooted my laptop with both firefox windows I had open and possibly a private window too, then rebooted again without touching firefox, and now I can only restore one of the two windows. I checked my recently closed windows in history and there was nothing there at all. Is there anything I can do at all to restore that other window or is it just gone for good now?

When I do this:

Click the menu button Fx89menuButton to open the menu panel. Click Bookmarks and then click the Manage bookmarks bar at the bottom. In the Library window, click the Import and Backup button and then select Restore.

I get a blank slate. No files listed.

When I go into the Profile, I see C:\Users\whatt\AppData\Roaming\Mozilla\Firefox\Profiles\shgdgxn6.default-release-1752271533405\bookmarkbackups

How do I restore bookmarks from that file?

Just updated to FF 141.0.3. The browser had advised me to restart to finish the update. So I did. But in doing so, not all my tabs were recovered.

Most were, but like 3 were not.

I was asked to create a new profile in order to keep using Firefox, despite never having an account. After I clicked okay, it opened the new version of Firefox, but without all the passwords, bookmarks and history of the past few years. This is really inconvenient. I have since then made an account, but the fact that I can't find any of this data anywhere has me worried that every time I update Firefox it will wipe my account.

Hello

So a funny story happened today, I used CC cleaner to help clean my PC now I have it set up so it does not touch Mozilla in anyway yet after an update those settings got wiped and when I used the program it wiped out everything I had in Mozilla, history, saved passwords, tabs, EVERYTHING.

The last time I made a backup to my bookmarks was 6 months ago, a lot has changed since then, I tried to use the restore function however those also got wiped out, so I decided to use the old bookmarks, yet it doesn't work, for some reason it tells me that it doesn't have any bookmark data in the file yet Chrome can read and import the bookmarks from the file, if I try importing stuff from Chrome it also comes up empty, as an experiment I made a new export from Mozilla and tried to import it and got the same error. I still have 2 bookmarks and those can't be deleted no matter what I do, I kept trying to delete them however they are stuck there no matter what I try. This laptop is a new one I got on the cheap after my laptop had a problem with it's hard drive, I made the backup right before the switch.

Does anyone have any ideas about what exactly happened and keeps happening?

I opened a profile that I had just used recently to a blank tab bar. I closed it and the sessionstore-backup folder did not have a recent backup, The most recent about a week old.

Just for testing, I tried to restore with one of the upgrade.jsonlz4 file, about 2 weeks old, but it also had no session. I then restored one that was 2 months old. That one had a session

Now, Firefox no longer generates the upgrade.jsonlz4 files

Since updating Firefox on June 30, 2025 on my Dell desktop computer that runs Windows 10, most of my bookmarks are no longer visible. Only four of my bookmark folders are visible and most of their contents have disappeared.

However, 1) my uncategorized bookmarks - those in "other bookmarks" are still visible, and 2) If I go to "Manage bookmarks" and do a search, I can find all of my bookmarks including those that are no longer visible.

In addition, I can no longer add or delete bookmarks. It looks like I can do add a bookmark and it will let me go through the steps of adding a book mark - it even says I can put it in all my old folders that are otherwise no longer visible. But one I complete the process the bookmark does not show up.

I have read multiple Firefox Help articles about disappearing bookmarks and have taken all the steps suggested including: - Attempted to restore backups of bookmarks - didn't work. It shows me the multiple old backups but when I try to restore one I get the message "Unable to process the backup file". I have tried it with at least four of the old backup files - all without success. - cleared cache - did troubleshooting mode - refreshed Firefox - uninstalled and reinstalled Firefox - looked to see if I had a different profile other than my default profile that I could switch to. I do not see another profile.

Nothing has helped. Any suggestions would be greatly appreciated.

Thanks

Hi All,

My laptop got damaged this morning and now that I am logging into Firefox with my new laptop its not syncing anything. Many years of bookmarks and stuff is just gone. Is there any way to get it back?

Kind Regards

I power cycled my computer in order to install some Windows updates, and when I opened up Firefox again, I had precisely zero bookmarks.

I found this folder, which is supposed to contain my automatic backups: https://i.postimg.cc/bwrWBswd/A.png

But I can't figure out how to use those files to restore my bookmarks.

When I click on Manage Bookmarks > Import and Backup > Restore > Choose File, nothing happens. No other option seems viable.

I had an ASSLOAD of bookmarks on this browser, so I need to recover them because there's just no way I'll be able to remember them all manually and add them all back one at a time!

What do I do?

I need to recover a `.jsonlz4` file to restore a Firefox session with 8 active instances, as the "Restore Session" feature only opened 5 due to the `browser.sessionstore.max_windows_undo` setting being capped at 5, and the full original `.jsonlz4` file is now missing.

In the`firefox/Crash Reports` directory, there are numerous files I can’t interpret, can I retrieve my session data via telemetry or other methods using this crash information. I’m using Linux Mint with Flatpak Firefox, and I also have crash logs containing a "last crash" text file and a string of numbers, could these be useful for getting back my session?

I've been backing up my opened tabs for the past 4 or 5 years with the steps in this legendary post: https://support.mozilla.org/en-US/questions/1257866

But this time it failed me and I don't know why. I just switched from Debian to Linux Mint, put everything up to date, but when I copy the sessions-store folder back into my session folder, as described in the post, nothing happens. I tried restoring only the 2 files listed there, and also dropping them in the general user folder, outside sessions-store, but still nothing. I've also noticed that the sessions-store folder isn't created automatically, even if I open a bunch of new tabs now and close the browser.

I don't even know how to begin troubleshooting this to be honest, this is the first time this method's ever failed me :(

I also saw this post: https://support.mozilla.org/en-US/kb/how-restore-browsing-session-backup But it doesn't help either.

Hey there! It seems that my bookmarks are gone. I only see the place holder for them, but no link or anything else. What can I do? Is there a way to import the bookmarks from the Mozilla website? Curiously the bookmarks on Firefox Android are there, but I can't see an option to export the list from there. Many thanks for any help! Best, Wolfram