Firefox Community Forum

Subject: Firefox Sync appears to have erased all bookmarks after setting up a new Windows installation

Hello Mozilla Support,

I believe I have encountered a Firefox Sync issue that resulted in the loss of my entire bookmarks collection.

Here is exactly what happened:

I have been using Firefox Sync for several years without any issues. This was not my first Windows reinstallation. I have restored Firefox through Sync multiple times before. Firefox Sync had always synchronized bookmarks, passwords, history, extensions and open tabs correctly across my Windows PC and Android phone. I had approximately 350 bookmarks, organized into folders. Timeline Yesterday I performed a clean installation of Windows 11. I installed Firefox 152.0.5 (64-bit). I signed into my existing Firefox Account. I did not immediately enable Sync, so nothing was synchronized at that point. Today I enabled Sync and waited for the synchronization to complete. Passwords synchronized successfully. Browsing history synchronized successfully (it took a little longer). Extensions were restored successfully. Bookmarks never appeared.

Immediately after noticing this, I checked Firefox on my Android phone.

At first, one of the bookmark folders still showed that it contained more than 300 items (I saw the item count), but when I opened the folder it was completely empty. After synchronization finished, all bookmarks disappeared from both devices.

Additional information Browsing history is still present. Saved passwords are still present. Extensions are still present. Open tabs synchronization continues to work. Bookmark synchronization is enabled. I am signed into the correct Firefox Account. The second local Firefox profile is empty. The automatic bookmark backup now contains only the current state (7 items), indicating that the original backup has already been overwritten. The current profile contains both places.sqlite and places.sqlite-wal. The only Sync error log is related to a temporary DNS lookup failure (NS_ERROR_UNKNOWN_HOST) and contains no bookmark synchronization errors.

Because history, passwords and extensions synchronized correctly, this does not appear to be an account or authentication problem.

What concerns me most is that I briefly saw the bookmark folder still reporting over 300 items on Android before it became empty. This makes me suspect that something went wrong during bookmark synchronization rather than the bookmarks simply never existing on the server.

Could you please advise:

Is there any server-side recovery or investigation that can be performed for Firefox Sync bookmark data? Are there any diagnostic logs that I can provide? Is this a known issue with Firefox Sync after connecting a newly installed device?

I would greatly appreciate any assistance, as this bookmark collection had been accumulated over many years.

I have a Sync error log available: error-sync-1783454370913.txt

It only contains a DNS error related to tabs synchronization: NS_ERROR_UNKNOWN_HOST

There are no bookmark-related errors in the log.

Thank you.

Spellchecker does not function, and in my most important projects, Gemini and Substack, no spell checking takes place, I have to switch to Chrome of all things...here in this field spell-checking is taking place...why?

I have spent much time researching this issue, made all the intervention recommended, nothing works, and the failure is 'selective', works on many things, fails on important production browser interfacing.

I value being Chrome-free, please help me solve this issue

Firefox drop down history shows about 85% favicon substitution for gmail entries. It is not the gmail favicon, it is a food blog I do not login to and only very occasionally read. It is a very random substitution.

Clearing cache, cookies and restarting did not eliminate the issue. All apps and browsers are fully up to date.

I only use Firefox so do not know if it happens on others. Also, it does not happen all the time, only about 85% of the time, sometimes within one session, as visible in the attached screenshot. The bottom 9 are gmail's and you can see it has chosen to substitute the gmail favicon for an unrelated food blog favicon, but the there are several gmail entries that display the correct google favicon.

It isn't a problem but it does make me feel less secure as it is a weird glitch. If there is crossover there, where else may there be identification failures? Is there any way to correct this? Thank you.

Hello community,

I've been moved to MacOS at work and since then, Firefox will not always restore my pinned sites when I start it the next day.

Here is what I do:

1. Right click a tab, select "Pin Tab"
2. Go about my day
3. At the end of the day, I close Firefox by using command Q and shutdown my Mac
4. The next day, I start Firefox and most of the time, my pins are gone

I did not have this issue on Windows Firefox. I am using MacOS 26.5.2 and Firefox 152.0.4 Firefox says "Your browser is being managed by your organization" in settings. It is a link that can be clicked and the only active policy showing there is "DisableAppUpdate" which I assume is because we have our own tool to manage software updates.

Any idea what could cause my pinned tabs to disappear? I did not really customize the settings so far, I do NOT clear browsing data when exiting FF and the startup option "Open previous windows and tabs" is NOT selected. I have Ecosia and 1Password as plugins.

Any help appreciated, thank you.

July 13, 2026

In Windows 10, FIREFOX is preventing the proper operation of the Windows 10 feature called MOUSE KEYS when FIREFOX is operating. MOUSE KEYS is a very important capability to individuals with certain disabilities.

MOUSE KEYS enables the use of the numbered keys on the NUMERIC KEYPAD to be used to move the cursor around when the NUM LOCK key is turned ON, as a substitute for using a mouse. Does Mozilla have a way to prevent FIREFOX from defeating this MOUSE KEYS feature?

Google AI indicated that there is a solution specifically for FIREFOX. That capability is built into FIREFOX and begins by using "about:config" to reset a parameter named "permissions.default.shortcuts" from either "0" or "1" to "2". I successfully implemented the steps in this solution by changing that value from its default value of "0" in my computer system, to "2", but no change resulted. MOUSE KEYS continued to malfunction in the same way.

After exhaustive testing looking for a pattern, I finally found one. The malfunction appears to be the following: With the MOUSE KEYS feature activated in the WINDOWS 10 set up, and with NUM LOCK turned ON to assure that this function is ON, each of the numeric keys, 0 through 9 on the keypad, cycles through the different MOUSE KEYS functions of all ten of these keys, in ascending order by their number. For example, if you press key 7 for ten times in a row, it will cycle through each of the ten MOUSE KEYS functions associated with the keys 0-9 to occur, returning on the tenth press to the function that was executed the first time that key 7 was pressed, and so one endlessly through multiple cycles. And similarly for each of the other ten numbered keys.

A similar type of malfunction of MOUSE KEYS occurs with any BROWSER program that I have tried, including GOOGLE CHROME and BRAVE. I gather from GOOGLE AI that browser programs INTERCEPT the codes generated by the numeric keys on the numeric key pad and change those codes before sending the codes to the WINDOWS 10 operating system, and thus to MOUSE KEYS, for execution, causing this problem.

Is there a solution for FIREFOX what will restore the proper function of the MOUSE KEYS feature of Windows 10, when FIREFOX is being used? Thank you for any help that you can provide.

Hi, I have been using Firefox for Windows for almost three decades. I have an ASUS VivoBook with a fully patched Windows 11 Home Edition 64bit operating system. Firefox is my default browser, with Microsoft Edge as the back-up should things go awry. Well, they have with this Firefox upgrade. It effectively blocks me from using my NordLynx VPN. There is no connectivity at all if I have the VPN on. If I pause it, then no problem. What gives? This has never happened before.

Nord VPN has already been given permissions through my Windows Defender Firewall. So how and why are you programming a solid wall against my utilizing it's functionality?

I would like your input before I start hard troubleshooting, since this is totally on your end.

BK

Top browser menu bars seam rather large and take up allot of space how do I reduce their size. Also and this is a Huge issue! The VPN network sign-in keeps popping up but I don't want to use the VPN. I already have another automatically running and it causes huge slowdown. Please help! Thanks!

Numerous tabs appear whenever I open Mozilla. I have used them at some time in the past, but never all on one occasion. SOME WERE LAST USED AT LEAST SEVEN MONTHS AGO.

Related may be that sometimes when I follow a link on one website, the destination appears on my screen as a new opening of Mozilla. The previous site(s) are completely obscured

Windows 11 expensive high performance tower PC. When I am closing Firefox I am warned that I am about to close 80+ tabs although. I actually had only 13 tab groups (closed) and one ordinary tab open (The New York Times) I close Firefox anyway and ALL the group tabs disappeared.

Sometimes, when I am warned that I am closing 80+ tabs, they luckily they haven't disappeared upon restarting Firefox. This happens often.

I know how to reconstruct my tab Groups proceeding from listing all tabs.

Sometimes the tab groups don't disappear. It makes no difference whether I start a Firefox session on my just rebooted PC (and run PC for a minutes only using Firefox) or not. When I recently closed Firefox I could see from task manager that there was minor activity showing in the Firefox app which surprised me. I hope you have an idea of what might be occurring. I'm not a novice, I purchased my first PC in 1989

Thank you, Anita

Moderator note: This question has been edited to fix the formatting.

I tried to use 'Change location' in the weather widget on the New tab page. I can type my location name in the search box, but it doesn't give any results. Thanks for reading my question!

Firefox completely changed overnight without notice and I have lost all my bookmarks and can't find out how to access TV channels that were easily available previously on my desktop. Trying to make sense of changes but struggling. Nothing that used to work for me is still available. I don't even recognise it. Might have to give up Firefox.