I have to add something.. I sit here rather baffled. Friend came by, we sat outside and I left with 4 tabs open, didn't even start to add what was lost. Now came back about 2 hours, 2 beers and 3 joints later (legal where I live ^^) and the tabs look exactly how I had it and needed it back, went from about 4 tabs to 48 tabs. Nobody clicked anything, it just changed... wft am i missing? No restart, was not on any logon screen as my desktop never times out.. it just changed back without any input. Do I like that.. honestly no. Can somebody explain me what is going on??

Are you signed into a sync account?

I have a owncloud running on my production folder on a different drive (F), nothing else gets synced.

The 4 tabs I had open are not at the end or start of the 're-set' tabs list either.. also not in the recently closed. They went bye bye.. I know what was open, as I had a crypto issue to sort with a Base transaction.. my account isn't base enabled, so had to get the junk recovered back to the sender.

Did you check "History -> Restore Previous Session" and "History -> Recently Closed Windows/Tabs" in case you had unnoticed windows ?

Use one of these to close Firefox if you are currently doing that by clicking the close X on the Firefox Title bar, especially if you have multiple windows or Private Browsing windows open to prevent losing tabs in unnoticed windows.

• "3-bar" menu button -> Exit (Power button)
• Windows: File -> Exit
• Mac: Firefox -> Quit Firefox
• Linux: File -> Quit

When I say till recently.. I work with Firefox for 2-3 months. Zero issues.. I do a lot of picture work with several editors open at the same time. But did that for months now and worked fine. Just yesterday evening it started. Had all open, went to the editor and when I came back my firefox was gone. Opened again and didn't got the tabs back, was the only open window of firefox.. then i added my tabs again, which I needed to do my picture reworks. Morning restart was fine, middle work, after about 3 hours editing, same, firefox gone with no error, i just swap out of the browser after pressing download and go explorer to start the edit procedure.. when I want to go back on the browser it's gone and I have to restart.. with no tabs, only one window. Nothing changed in the settings.. when ever I check.. open the recent blah blah is checked with a hook. And it happened once so far.. suddenly all tabs are back without any key interaction. I did install Filmora8 a few times yesterday with Wondershare support, old projects didn't load. Is the only stuff I did.. didn't work on pictures as I was busy with old Filmora projects to change to 2024

Do you have tab related extensions?

Start Firefox in Troubleshoot Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration or if userChrome.css/userContent.css is causing the problem.

• switch to the Default System theme: "3-bar" menu button or Tools -> Add-ons -> Themes
• do NOT click the "Refresh Firefox" button on the Troubleshoot Mode start window

• https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

Did you check "History -> Restore Previous Session"

I do not see this option in my history page. Recently closed tabs, I see, like recently closed windows. The tabs I created before the last crash are in none of both. Just gone... I feel rather unsure to work with the uncertainty that I loose my browser setup at random.. what would you do? Reinstall and risk it or simply go the safe way and use a different browser as something is clearly not working how it should.

Closed Firefox and restarted with holding shift. Starts with one window all tabs gone (48), which I am using right now to write.

^^ sorry, made edit compared to the picture.. but I hover the mouse over firefox to show.. fresh start, one window only.. no tabs anymore.. and they are not in the recently closed either.. doesn't add 48 lines.. stays exactly the same.

I can also close and start as often as I want.. tabs gone... takes a bit to add em again.. not doing that till is sorted or i run a less buggy browser

I never used or had chrome installed.. and will also not happen. The only addon i use is Telegram Web, no themes or anything else installed.. naked Firefox installation with the latest Telegram Web version running

So far never happened again.. can report that too. So have to consider too that I did something stupid. Is there a key combo to kill the tabs?

Did you previously see "History -> Recently Closed Windows" as there might have been an unnoticed window? Were you previously using the close X on the title bar to close Firefox and not Exit in the menu to close Firefox like I posted above ?

I close always over the X.. always.. what ever app.

If I always have the same tabs open, would it make a new save for recent closed windows or would it see that there is a same setup saved and not make a new one?

Firefox works differently than most other applications and you can have multiple windows open, not only browser windows, but also Windows like the Bookmarks Manager (Library) count as such. If you use the close X of a window, then you only close this specific window and only if you close that last window, then a close down is initiated and session data is saved to the profile folder including open tabs in sessionstore.jsonlz4. This means that only the last closed browsing window will be restored and three other browsing windows can be reopened via "History -> Recently Closed Windows", but the windows do not open automatically like happens if you use Exit/Quit via the menu.

I have had this as a longstanding problem. If the history window is open and the program crashes, usually as a part of a windows crash or power loss, the main window is lost, and cannot be restored with RESTORE PRIOR SESSION.

The last closed window is not a usable window and often multiple tabs are lost. I have found a way to one by one try to get them back with sync, to a limited degree. Big recurrent problem , with frequent lost work.

Any things I could be doing or is this intrinsic to FF? Perhaps not addressable, as desired at some level.