Firefox Community Forum

With the "Open previous windows and tabs" preference checked on a PC (don't know if Mac or other has this issue), if you had multiple windows open, closing all of them at once via "Close all windows" in the Firefox app's Tasks menu on the taskbar (with multiple windows open, right click the Firefox app on the taskbar to open the Tasks menu, then click "Close all windows"; if only one window open, it'll say something singular instead of plural), it used to be so that when you try to reopen Firefox, all your multiple previous windows would reopen. Instead, it now only reopens one of them, I think maybe the last window you were looking at.

Now you could try to reopen the other windows via the History -> Recently closed windows, but that's assuming that the other windows are saved onto there, because it seems that there are times when they are no longer saved there.

I'm not sure this is for sure the reason why it's no longer in History anymore, but my place has had some electrical work being done by the city outside, so twice there have been notices given that the power would be shut off within a short period, meaning twice my PC was shut off within that short period. My guess is that after it shut off the first time, I had that short period of time to reopen the other closed Firefox windows because it was indeed saved in History, but I didn't notice that Firefox didn't reload ALL of the windows - only one. So when the power shut off a second time, that history was lost. This is just a guess - maybe Firefox auto deletes it after some time, idk. But mine are no longer there, so fml I guess.

I also tried sessionstore-backup, but the earliest one was within the last 2 weeks and the other windows still were not in the History.

Is there some second Preference checkbox option that needs to be checked, or can y'all change it back to what it was before?

Sometime between 10PM 7/23 and 2 AM 7/24 I deleted my profile by mistake, and all of the data my browser collected has been lost. Passwords, history, cookies, chat logs, etc. No account sync, or official Mozilla profile until now.

Everything is gone and I don't know how to replicate the steps found in this video. Mac's don't conveniently show you things like deleted user data unless you know exactly where to find them. [|https://youtu.be/JWJwmKLqnZs?si=g_g47eHSwoB8XSL5]

I've already tried using Time Machine, but that failed spectacularly.

Current OS is macOS Tahoe 26.5.2, Firefox 153.0 (aarch64)

Hello Mozilla Team,

I'll directly jump into - 12 years of Bookmarks and history are gone after the last update. No warning or anything. Can you help me restore? That's unbelievable.

My wife's old Windows 10 HP laptop quit working last week do to some Operating System failure while it was trying to do an update. It finally did a reboot and now it is useless, at least as it is! It will NOT complete the boot process after trying all of the options offered. All that I am able to is exit out of Windows to a "DOS prompt." I am able to get to the Mozilla Firefox folder and others contain within. The new Windows 11 laptop I bought her is working fine with a fresh Firefox browser installed about a week ago. What she wants is her web links, settings and saved passwords "copied" from the old laptop and installed on the new one! We have no idea how many there are to retrieve! I'm hoping that there might only be one folder that I can copy via "command line" prompt to a USB drive and move the file(s) to the new laptop the same way. Can anyone tell me what I need to know? Thanks in advance! Tim O.

I have tried to follow various help files, but can't recover any bookmarks. Everything bookmark related seems to have completely disappeared. I have the current bookmarks backup from my laptop, but when i go to the bookmark library and click on "import bookmarks from HTML" nothing happens. I am on an iMac OS 12.7.3, Firefox 150.02

You forced an update and all my open tabs vanished into thin air. I was working with those!!!

I tried to follow the history recover path, no-go. I tried the json file path and can't get Firefox to open the tabs in the json recovery file from a month ago, not that that would be helpful anyway since I want yesterday's before the update!

Now I gotta spend a lot of time finding those scientific papers again - should charge you my hourly rate for wasting my time.

It's sh.it programming that's what it is. Bet you they were using AI to do the update.

Well never mind, I've grown tired of Firefox anyway since it just starts using 80% of my RAM when I have more than 10 tabs open. There's other browsers.

Recently my installation of Firefox (Windows 10, 64 bit) updated. Now my bookmarks are apparently gone--or at least I can't see them. Furthermore, I can't bookmark anything at all, so I don't have the option of laboriously rebuilding my library of bookmarks. I don't know how to recover what I had, or even if I can at all. Nor do I know how to alter settings so I can add new bookmarks. Could someone please assist? Thanks.

I opened my computer after dinner and Firefox was gone and I have to start all over again! It wants a Mozilla account & sign in which I don't have. All my bookmarks are gone!!! It's all lost!!

            Elaine Fink

Lost all tabs during an update including(weirdly) all theme stuff. Its not in the restore in history. But the themes part is the one that is strange, because why would themes change during an update, all while all my tabs are lost?

So, whenever my Firefox updates, it seems that it completely wipes my history, and deletes all my tabs, despite it being set to "re-open previous tabs on launch".

This has happened multiple times now and is really not fun. Do I just need to make bookmark folders for everything I do? Because having everything randomly delete itself, without even a session restore in the backups folder of my firefox profile, isn't ideal.

I do have a sessionstore error for this, where I presume the problem is laid out.

1784409622095 SessionStore WARN SessionWriter.write, Caught exception:: NotFoundError: Could not move `C:\Users\SUCKS TO SUCK\AppData\Roaming\Mozilla\Firefox\Profiles\sphzxgst.dev-edition-default\sessionstore.jsonlz4' to `C:\Users\SUCKS TO SUCK\AppData\Roaming\Mozilla\Firefox\Profiles\sphzxgst.dev-edition-default\sessionstore-backups\previous.jsonlz4': source file does not exist (NS_ERROR_FILE_NOT_FOUND) No traceback available 1784409622095 SessionStore ERROR Could not write session state file : NotFoundError: Could not move `C:\Users\SUCKS TO SUCK\AppData\Roaming\Mozilla\Firefox\Profiles\sphzxgst.dev-edition-default\sessionstore.jsonlz4' to `C:\Users\SUCKS TO SUCK\AppData\Roaming\Mozilla\Firefox\Profiles\sphzxgst.dev-edition-default\sessionstore-backups\previous.jsonlz4': source file does not exist (NS_ERROR_FILE_NOT_FOUND) No traceback available

This isn't exactly something that is broken but it is something that is plenty weird and I wondered if anyone has an idea how it happens.

I shut down my Linux laptop one day and when I started it the next day, all my tabs were gone. Annoying, but I spent some time searching for the most important ones and got on with my life.

We have a class picture book that is only accessible by faculty from campus or using the secure VPN. It helps us to learn people's names. It is an HTML file. One day, I needed to look someone up. Ordinarily that would open a new tab in the browser I have running, but it didn't. A whole new Firefox appeared for it and there were all my lost tabs.

Wut?

Now I can use the picture book to alternate between my old tabs and my new ones. How on Earth can this happen? It isn't exactly something that is broken, just something I don't understand.

I had a catastrophic failure of my desktop computer. They were unable to recover over half my files. My bookmarks in Firefox had links to several critical business pages and I really need to get them back however I have been unable to access them or recover them. Is there any way for these to be recovered if the backup wasn't on? I know its a long shot but I have to ask.

I was using my web browser and I tried to load a pdf on word. The Mozilla asked me to sign in and all my bookmarks and history was gone. A VPN was up in the tip right hand corner appeared that I had never seen before. I have no idea how my original homepage disappeared and all my bookmarks with it.