If your trying to save tabs to open when you start FF you could pin them. I do this and it works every time for me. To Pin tabs: Two finger click on the tab (touch pad) or right click > Press Pin tab.

As for the other issues have you tried starting in safemode? https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode

Or you can try resetting firefox to its defualt settings (while saving your data) https://support.mozilla.org/en-US/kb/reset-firefox-easily-fix-most-problems

Oh, yes, this problem also occurs with some software updates where the updater launches a page in your default browser.

The session restore feature is fragile: only one session is stored. When you direct load Firefox with a specific URL, it bypasses normal startup behavior. So when you opened and closed Firefox for the help file, your "real" session was moved from the regular sessionstore.js file to sessionstore.bak. When you re-opened Firefox again, that old session was tossed and only the help file session was available to restore.

But you may have some other things going on here based on your ongoing issues. Could you check your profile folder for any "extra" sessionstore files? Here's how:

Open your current Firefox settings (AKA Firefox profile) folder using either

• "3-bar" menu button > "?" button > Troubleshooting Information
• Help menu > Troubleshooting Information

In the first table on the page, click the "Open Folder" or "Open Containing Folder" button

Scroll down and look for sessionstore.js (which should have a very current timestamp) and sessionstore.bak (which should be dated as of your previous session). You may also find sessionstore.bak-datetime created during your last Firefox update.

Do you find any extra files, such as sessionstore-1.js or other numbered files? If so, that indicates that Firefox cannot write to the main sessionstore.js file because it is locked or corrupted, and your windows/tabs are being saved in a numbered file. Unfortunately, Firefox can't actually restore any of those files automatically. In this situation, I believe you need to remove the sessionstore.js file (after exiting out of Firefox) and copy the latest numbered file to sessionstore.js.

If you use "Show my windows and tabs from last time" as the startup setting then Firefox won't show a quit warning because under normal conditions you won't lose the tabs as they will reopen automatically. In your case you opened Firefox via an external application to a specific page and in that case the behavior is different like posted above. Once you close and open Firefox another time then the sessionstore file with that previous session will get lost.

You can look at the Session Manager extension to backup your sessions and extend the support of the built-in session restore to manage and save multiple sessions.

• https://addons.mozilla.org/firefox/addon/session-manager/

Thank you Sir.Mayo, jscher2000 & cor-el for your comments.

I just learned about "Pinning" tabs (Sir.Mayo) and wondered about that. I will test it.

jscher2000's & cor-el's comments about external programs opening specific pages makes sense. In the future, I will be alert to using "Restore previous session" before closing FF.

jscher2000's comments about multiple backup session files hit home. I find one extra backup dated July 31. I will try copying it to "session.js" and see what happens.

Here's an interesting thing: I examined "session.js" in a text editor. I see many references to several of my long-kept but now missing tabs and their URL's in there.

The info is clearly there, but FF is not using it. A corrupted file, perhaps?

I will do some testing and report back. Other chores today - may take a few hours.

Hi EStar, by default, Firefox remembers a certain amount of history for each tab you had open (up to 10 pages, I think), a certain number of closed tabs (up to 10 tabs per window), and a certain number of closed windows (up to 3 windows). So... when you look at the file directly you normally will see that data in addition to the windows and tabs you were last looking at.

To access those from within Firefox, after using Restore Previous Session (or restoring your session automatically), check the History menu for closed windows and closed tabs.

Also, it might be a typo in your post, but just in case: Firefox doesn't look for session.js but sessionstore.js when starting up.

Yes, you're right jscher2000. My typo. I wasn't looking at the listing when I typed it.

But you just explained why I see so many references to my old tabs in there.

You two (jscher2000 & cor-el) put me onto a great trick!

Displaying the text of a sessionstore file in a separate window manager window and switching between it and FF, I was able to use FF's History Search to find and recover all of my old tabs!

For readers who want to do this and are not clear what I mean:

1) Open Firefox, and open its History sidebar (3 Bars -> History -> View History Sidebar). 2) Find your profile folder (3 Bars -> "?" -> Troubleshooting Info -> Open Folder) 3) Now minimize FF. 4) Open your profile folder in a separate window manager window. You might need to make your window "Show hidden files". 5) Locate the "sessionstore.bak" file. 6) Use a text editor or display program to display the contents. It's just a plain text file. Linux users might need to use "sudo" to open anything in there. DO NOT CHANGE ANYTHING! 7) Looking through the gibberish, you will see bits of page and file names of your old tabs. 8) For each one you identify, bring up FF (un-minimize), open a New Tab and type an identifying word or words into the Search bar at the top of the History Sidebar. It will promptly reduce the History display to only those entries containing what you typed. Click on one that looks right. FF will promptly display that page (if it's still online). If that's not right, try another. One of the entries has to be your missing tab. 9) For extra protection, list your tabs (or clues to them) on paper. 10) Now close FF, then open it again and see if it kept your tabs.

This does not solve the problem of FF losing tabs, and it's not an automated recovery, but it does provide a workable and not too difficult recovery method! I just learned a valuable FF lesson!

Thank you jscher2000 & col-el!!! The world thanks you!

I'm going to mark this thread "Solved" since it did allow me to recover my tabs.

I flagged cor-el's answer as "Helpful", and the system showed a 1-heart symbol under it, but it didn't flag it with the yellow "Helpful Answer" label.

OK, now it does. I don't get it.

Note that you can open such a sessionstore.js file in the Scratchpad (Firefox/Tools > Web Developer).

• https://developer.mozilla.org/Tools/Scratchpad

That editor has a toolbar button labeled "Pretty Print" that formats files in JSON format for easier reading.

Wow. Thank you, cor-el. I didn't know that. Handy.

I have revoked the "Solved" setting.

After my last post, I followed cor-el's suggestion above and changed my Preferences (General) from "Show my windows and tabs from last time" back to "Show my home page".

When I closed FF, it obligingly displayed its usual multiple-tabs warning, with the usual option to "Save and quit". I did.

But it didn't save. When I opened it again, it only had the one home page tab.

More investigating and testing. I'll report tomorrow.

You need to restore the previous session with that startup setting.

Doesn't that give you the previous session?

No it doesn't. Suddenly FF will not save tabs, even though it still has the settings that say it should.

Does anyone understand FF's tab-saving mechanism? Could Caja's launching of FF have "broken" something?

Where does FF store the "saved tabs" info?

I may have to remove and re-install FF from the repository. I'd like to save my history so I don't lose it.

Hi EStar, earlier in this thread (post)I detailed exactly where Firefox saves your session history. If you check those sessionstore files again, can you determine whether they are being updated in real time (by default, Firefox will update every 15 seconds if there are changes).

If we aren't able to get to the bottom of the problem you could consider using Firefox's Reset feature. This article describes what is kept and what is lost: Refresh Firefox - reset add-ons and settings.

It would seem to me that all that is necessary, is to change the option back to: "Show my windows and tabs from last time" Shut down FF. Delete the: "sessionstore.js" Rename the: "sessionstore.bak" to: "sessionstore.js" Restart FF. Has worked for me in the past.

Bill

SUCCESS!

Here's what worked:

1) Yesterday I installed Session Manager (then had to deal with various other matters).

2) Today:

    a)  I renamed my "sessionstore.js" to "sessionstore.bak-(today's date/time).
    b)  I copied that July sessionstore backup file to the desktop, renamed the copy "sessionstore.js" and put it back.
    c)  Restarted Firefox.  Session Manager promptly popped up a dialog box asking what tabs I wanted to restore.  I recognized all my old tabs, so I had it restore everything.
    d) Closed FF with "Save and quit".
    e)  Re-started FF.  It came up with all the tabs, just like before.

I "lucked out" here in having that July 31 session backup I did not even know about.

Many thanks to jscher2000 and cor-el for your helpful guidance.

billmcct, your idea sounds good too, except that in this situation that backup file got set to match the ".js" before I realized what was happening. So it would not have helped here. Thanks for sharing it, though.

Glad you got it fixed. I had read the post and then received the email.

Bill