You may have corrupt sessionstore file(s). Delete all sessionstore* files and the sessionstore-backups folder.

Type about:support in the address bar and press enter.

Under the page logo on the left side, you will see Application Basics. Under this find Profile Folder. To its right press the button Show Folder. This will open your file browser to the current Firefox profile. Now Close Firefox.

Locate the above file. Then rename or delete it. Restart Firefox.

FredMcD said

You may have corrupt sessionstore file(s). Delete all sessionstore* files and the sessionstore-backups folder. Type about:support in the address bar and press enter. Under the page logo on the left side, you will see Application Basics. Under this find Profile Folder. To its right press the button Show Folder. This will open your file browser to the current Firefox profile. Now Close Firefox. Locate the above file. Then rename or delete it. Restart Firefox.

Thank you so much Fred, but after clicking "Show Folder" I didn't see "Close Firefox". I need a little further hand? And thanx again!

You close Firefox the same way you close any program.

Hi Adelaa, the "Restore Previous Session" function is also available on the History menu. On Windows, you can find that either:

• "3-bar" menu button > History > Restore Previous Session
• (menu bar - tap Alt if needed) > History > Restore Previous Session

If the menu command is grayed out and nonfunctional, then either:

• Firefox already restore the session, check the History menu for previously closed windows and tabs to see whether they are available there
• Firefox did not find a previous session history file (for some reason -- to be determined)

Oh I'm sorry I thought you meant a link. But I went on and found a very long link of many letters and numbers and in the middle the word "default". I tried to delete it and it took me to another file...then I quit. It's so embarrassing not to understand all of this... I may try it again when I have more time to figure out those pages. But i thank you for trying to help me.  :o)

jscher2000 said

Hi Adelaa, the "Restore Previous Session" function is also available on the History menu. On Windows, you can find that either:

• "3-bar" menu button > History > Restore Previous Session
• (menu bar - tap Alt if needed) > History > Restore Previous Session

If the menu command is grayed out and nonfunctional, then either:

• Firefox already restore the session, check the History menu for previously closed windows and tabs to see whether they are available there
• Firefox did not find a previous session history file (for some reason -- to be determined)

Thanks so much jscher! The menu, as you said, was greyed out so I tried the previously closed windows and tabs but it wasn't there. I then searched Google and got a little easier formula:

“Menu >options >general panel >from Firefox dropdown: Show My Windows and Tabs From Last Time >close window. Any changes you’ve made will automatically be saved.” I was able to carry it to the end and restarted the computer...but when I tried it, the “Restore Previous Session” still wasn’t there...

I thank you very much for trying to help me and I wish you and Fred a Very Merry Christmas and a Happy New Year!  :-)

In case you use "Clear history when Firefox closes" then make sure not to clear the "Browsing History" because that takes prevalence and you can't reopen pages from the previous session.

• Options/Preferences -> Privacy -> Firefox will: "Use custom settings for history": [X] "Clear history when Firefox closes" -> Settings
  do not clear the Browsing History
• https://support.mozilla.org/kb/remove-recent-browsing-search-and-download-history

• clearing "Site Preferences" clears exceptions for cookies, images, pop-up windows, and software installation and exception for password and other website specific data
• clearing cookies will remove all selected cookies including cookies with an "Allow" exception you may want to keep

Hi and thank you cor-el. I didn't find "Clear history when Firefox closes" or "Browsing History", but in my page it says "Firefox will Remember History". Should I use instead "Use custom settings for history"?

Maybe you could tell me how i can find those other links you mention? Thanks again.

FOUND IT! lol! The box for "Clear history when Firefox closes" was blank, so apparently there must be another reason for the phrase Restore Plage not appearing?

Adelaa said

I then searched Google and got a little easier formula:

“Menu >options >general panel >from Firefox dropdown: Show My Windows and Tabs From Last Time >close window. Any changes you’ve made will automatically be saved.” I was able to carry it to the end and restarted the computer...but when I tried it, the “Restore Previous Session” still wasn’t there...

Firefox should have restored your previous session automatically after you made that startup setting change. Did the change get reverted back to "Show my home page" between the time you exited out of Firefox and the time you started it up again?

Hello jscher, it's a good question and I just went there to check, and no, the "Show My Windows and Tabs From Last Time" is still there.

I read (don't recall where since reading so many fixes not only this one but other problems as well) lol! that Firefox discontinued this function. But I think if it were so you and the other kind people helping me here would've said so...

Thanks for checking on me.  :-)

Adelaa said

I read (don't recall where since reading so many fixes not only this one but other problems as well) lol! that Firefox discontinued this function. But I think if it were so you and the other kind people helping me here would've said so...

Oh, it works, I've been using it for a while now.

But maybe your Firefox is not recording session history in real time, or has some limits set on it.

Check for Customized Preferences

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful.

(2) In the search box above the list, type or paste sess and pause while the list is filtered

(3) If any preferences starting with browser.sessionstore. are bolded (other than/not including the ones that start with browser.sessionstore.upgradeBackup.) they could be affecting what Firefox saves between sessions. Could you right-click > Copy and then paste into a reply any that are customized?

Check for the Actual Files

By default, Firefox updates your session history every 15 seconds (if there is a change), so the files should have very recent date/time stamps. Let's see.

You can open your current Firefox settings (AKA Firefox profile) folder using either

• "3-bar" menu button > "?" button > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

In the first table on the page, click the "Show Folder" button to launch a Windows Explorer window showing your profile folder contents.

In your profile folder, scroll down and double-click into the sessionstore-backups folder.

The kinds of files you may find among your sessionstore files are:

• recovery.js: the windows and tabs in your currently live Firefox session (or, if Firefox crashed at the last shutdown and is still closed, your last session) -- should have a very recent timestamp, since you just opened the Troubleshooting Information page
• recovery.bak: a backup copy of recovery.js -- should also be recently updated, maybe running 15-60 seconds behind recovery.js
• previous.js: the windows and tabs in your last Firefox session
• upgrade.js-build_id: the windows and tabs in the Firefox session that was live at the time of your last update

Could you take a look at what you have and the date/time of the various files to see whether Firefox is recording session history as expected?

Note: By default, Windows hides the .js extension. To ensure that you are looking at the files I mentioned, you may want to turn off that feature. This article has the steps: http://windows.microsoft.com/en-us/windows/show-hide-file-name-extensions

Oh thank you so much jscher!!! You did so much work for me and so neatly and clearly, I just hope I can understand it all. I got to your paragraph (3):

The only bolded line I saw was browser.sessionstore.upgradeBackup. and I copied it into my email until I know what means "...then paste into a reply any that are customized?"

I'm sorry to take so much of your time. Maybe I should've continued with the rest of your instructions despite mi little crossroad?

Hi again, I went to check the Actual Files and found the following with today’s dates, times 10:04 pm which is around my present local time, and each 368 Kb:

Previous

Recovery.bak - on opening this one it only said “How do you want to open this file” “Use store apps” etc.

Recovery

On opening “Previous” and “Recovery” they both had identical content as follows:

A very long link.

Line: 1

Char: 11

Error: Expected.

Code: 800A03EC

Source: Microsoft JScript complication error. (I suppose these 2 are js for JScript?

I didn’t see any files, so perhaps this means FF hasn’t been recording?

I shall try the next instructions you so kindly wrote for me and will report when i finish.

You shouldn't double-click the files as that makes Windows open the file as a JScript file and that fails, because the file has data in JSON format.

You can open the file in a Firefox tab to see if you can recognize links.

If you want to use such a file then you need to place the file in the main profile folder and rename the file to sessionstore.js It is best to set the startup to "Show my windows and tabs from last time" to make Firefox restore the session.

You can also open the file in the Scratchpad ("3-bar" menu button or Tools -> Web Developer).

• click the "Pretty Print" button to format the file for readability.
• https://developer.mozilla.org/Tools/Scratchpad

Adelaa said

Hi again, I went to check the Actual Files and found the following with today’s dates, times 10:04 pm which is around my present local time, and each 368 Kb:

It sounds as though the relevant files are being created an updated.

Could you check at the main level of the profile folder (the one that was first display when you used "Show Folder"). While Firefox running, this file should NOT be displayed: sessionstore.js (if you haven't set Windows to show common file extensions, it will just say sessionstore).

If you leave that folder open the next time you exit out of Firefox, what you would expect to find is that Firefox creates a sessionstore.js file so that it can restore your session at the next startup. At the same time, recovery.js and recovery.bak will be removed from the sessionstore-backups folder. Does that all happen?

Thank you cor-el and jscher. I just came back from spending the day out, I'll work on this tomorrow and will report. Thanks again to both of you. I feel bad taking so much of your times, i wish I could understand much better the labyrinths of the computer!  ;)

TO: Fred, jscher and cor-el:

I thank you all so very much for all of your help, but I'm having more pressing problems with Windows which interfere with my work, so I thought I can live with the absence of Restore Previous Page and try to fix my Windows.

I'll keep this thread link so I can come back to resume the fixing of this function when I succeed in fixing at least the Windows parts that so interfere with my work.

Again thanks so very much, and I wish everyone of you and their loved ones a Very Healthy, Prosperous and Happy New year!  :) Adela