Diễn đàn hỗ trợ Firefox

I added Firefox to my new laptop and needed to reset my password to login. I recognize a few of my old bookmarks at the top but all of my passwords and login information is gone and none of my old devices are showing up. I have never encountered this issue before, please help.

I believe I got an automatic update to Version 154.0 yesterday on my Windows 11 laptop. When I opened Firefox after the update I got stuck

My Bookmarks appear to still be available, but my passwords are gone. The passwords are still available on my iPhone and iPad

I have tried syncing to no avail.

I need my passwords. How can I get them back?

When I frequently turn off my computer using the system unit's power button, meaning a quick shutdown, after several such shutdowns, when I launch the browser, I'm prompted to log in again. Bookmarks that weren't synced disappear. And I'm also logged out of all the websites I was logged into, forcing me to log in again. Cachyos Linux.

I am using the same account (my school email), and everything else sync successfully.

Tab groups saved on my Windows PC didn't show up on my Macbook; tab groups saved on my Macbook didn't show up on my Win PC. Is this a feature or bug?

After reinstalling my computer system, I logged into my Firefox account again, but the data synchronization failed. All my previous data is gone, including bookmarks, passwords, and widgets. What happened? I can't find them in the mobile app either.

Hi there, I have been using the Firefox browser for many years and had saved all my login passwords to various sites on it and I never had a problem with it. But this time, after installing Windows and the Firefox browser, when I logged into my account and turned on the sync, it did not bring any of my previous information. When I go to my account management page, it writes my membership date at the bottom of the page as of today (2026), while as I mentioned, I have had an account on the Firefox browser for many years. How is it possible that my previous information does not exist and it recognizes me as a new user and what is the solution?!

Download FF install sign-in > said success then show warning

``` Are you sure you want to sign in to sync?

A different user was previously signed in to sync on this computer. Signing in will merge this browser’s bookmarks, passwords and other settings with xxxx@gmail.com ````

Press continue, the pop-up still appear and the sign-in was false positive.

FF version : 156.0 (64-bit)

I'm not given the choice to STAY LOGGED IN and every time the system logs me out, I'm going through the motions of restoring my bookmarks. Isn't there a way Mozilla could fix this by allowing the bookmarks to be restored to the last login or give the user the choice to stay logged in? Better yet, DO BOTH. You know your the ONLY web browser that I've ever used that fails to do this. I'm sure their are dozens of programmers that could spend 30 minutes coding this into program. A few lines of code or a HOOK to fix this.

I stopped using Firefox on my desktop and began using Edge until it was necessary to have a Microsoft account for it to fully function. Then and only then I returned to Firefox.

Help us out here people. This is a real "rock in the shoe" issue.

I have linux LMSDE7 Mint, Firefox will not sync. I click on the 3 top right corner lines, sign into Mozzilla, the bookmarks have not synced. Then if I go back to the same lines, it has still the "sign in" field, clicking has no reaction. It seems that mozilla is not signing in I have an other linux version, winux, there I have no problems, it syncs ok.

Hi Moz Support,

I've had this happen several times before, but this time it really annoyed me.

I sent tabs from one Firefox instance to another on another device. I closed these tabs on the source device. These tabs were quite old this time, I'd not opened them in a while - this becomes important later.

On the destination device, let's call it "madbilly's destination Firefox", these tabs didn't arrive. After doing a couple of tests where I sent a tab from my mobile to this instance, I realised that this was a similar problem to what I'd had before, which is one where a Firefox instance/profile for some reasons "resets" itself and it seems to create a new instance in Firefox Sync. Tabs which have previously been sent to "madbilly's destination Firefox" don't arrive, because (I think) it's not registered in Firefox Sync as the same instance. These sent tabs, if closed on the source instance (which I did) are lost, unless one reopens the source instance and Ctrl-Shift+T reopens closed tabs. Unfortunately, in this case because the tabs were old and I hadn't opened them for a while there was no way to do this, because Firefox doesn't remember closed tabs which are not stored in memory (another bug, any fix?), except for looking in old session store backups which I'm going to do after I write this post, though I don't know if that will work.

Also, on Android, because it only remembers 10 closed tabs it's not really feasible to retrieve lost sent tabs this way either, and as there's no access to the session store backups the tabs are definitely lost.

Oddly, when this happens "madbilly's destination Firefox" usually appears twice in the send-tab-to menu, but in this case it didn't. To be able to send to this instance I had to sign out of Firefox sync on this instance and sign in again. Then the same instance appeared twice in the sync menu, the old one being now unreachable.

I'd like to know: 1. Why does this happen? 2. How to avoid it happening? 3. Is there a bug registered about this? 4. When will it be fixed and prevented from happening again.

I generally find that this happens when a Firefox instance isn't shut down properly, which on my old desktop I put down to it running out of resources, but on this shiny new laptop from work that doesn't make sense.

All help much appreciated thanks :)

I am trying to sync FF to a new pc laptop from my old pc laptop. I am signed into FF on both devices, but they won't auto sync, even when the (orignal) says that it is. My old laptop is still running on Windows 10. Could this be the reason? If not, please advise how this can be accomplished.

I want to "synch"/ export/migrate my current tabs on my old computer to this computer -- the 'synch now' button in your settings doesnt seem to take it on - please let me know?

this is my back-up laptop, which until recently synced perfectly with the main one. now all bookmarks are missing, and I cannot understand what is happening the background.

Sehr geehrtes Support-Team,

ich habe seit Kurzem ein Problem mit Firefox auf meinem PC. Es erscheint folgende Fehlermeldung:

   „Das Lesezeichen- und Chronik-System wird nicht funktionieren, da eine der Dateien von Firefox von einer anderen Anwendung verwendet wird. Dieses Problem könnte von einer Sicherheitssoftware verursacht werden, beispielsweise von einem Virenscanner.“

Ich nutze dasselbe Firefox-Konto auf meinem Handy und auf meinem iPad. Dort funktioniert die Synchronisierung der Lesezeichen ohne Probleme. Das Problem tritt nur auf meinem PC auf.

Ich arbeite bereits seit mehreren Jahren mit Firefox und hatte dieses Problem bisher noch nie. In meinen Lesezeichen sind sehr viele wichtige Webseiten gespeichert, deshalb möchte ich diese auf keinen Fall verlieren.

Können Sie mir bitte mitteilen, wie ich dieses Problem beheben kann, ohne dass meine Lesezeichen verloren gehen?

Vielen Dank für Ihre Unterstützung.

Mit freundlichen Grüßen

Meik