If you check the History menu for recently closed windows or recently closed tabs, do you find any from your previous session you can restore?

To preserve all your session history files, please DO NOT CLOSE Firefox.

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

In the window that launches, scroll down and save a copy of all files whose names start with sessionstore to a safe location, such as your Documents folder. We may need them to recover your previous session.

Could you also check your desktop for any folder named Old Firefox Data? If Firefox encounters a serious problem it may perform a Reset and move your old settings folder to Old Firefox Data. It would be helpful to know whether that happened during your upgrade.

The kinds of files you may find in your new backup of sessionstore files includes:

• sessionstore.js: the windows and tabs in your currently live Firefox session (or, if Firefox is closed, your last session)
• sessionstore.bak: the windows and tabs in your last Firefox session
• sessionstore.bak-datetime: the windows and tabs in the Firefox session that was live at the time of your last update
• sessionstore-1.js (or other numbered files): windows and tabs saved at a time when Firefox was unable to update the sessionstore.js file

Could you take a look at what you have and the date/time of the various files to see whether you think any of them would have the missing windows and tabs?

By default, Firefox Windows hides the .js extension on files. To work with these files as accurately as possible, you can turn off the hiding. This article has the steps for that: http://windows.microsoft.com/en-us/windows/show-hide-file-name-extensions

jscher2000, thanks for coming to my aid.

I have some answers for you:

1. When I check the History menu, I can view Recently Closed Tabs & Recently Closed Windows and have often reloaded a Tab from this menu, so that works as it's supposed to. The problem is that Restore Previous Session is greyed out on that same menu.

2. I have also revealed the file extensions by following your instructions.

3. An Old Firefox Data Icon is on the Desktop, created in April 2014. I searched to see if there was a recent one and found nothing.

Now, I glaze over when I see the rest of your instructions. I will need to whip up some courage to attempt it. I will get back to you if I fail or hopefully to tell you I succeeded.

PS. Is there a way of preventing auto installing updates of Thunderbird? The latest version installed when I was checking which version was installed.

Hi Figgerty, how many folders are inside the Old Firefox Data folder, just the one from April? If you peek one level down into the semi-randomly-named profile folder(s) at a folder like sessionstore.js, you can get a sense of when that profile was last updated prior to the reset.

Regarding Thunderbird, I don't know, sorry. But there may be a support article on it here somewhere.

Hello again jscher2000. I didn't expect you to be back so soon.

The Old Firefox Data Folder contains the following 3 subfolders, the 'session' named files are listed below:

Sub folder \lyoiory7.default-141176885..... date modified 01/10/2014 sessionCheckpoints.json sessionstore.bak sessionstore.js

Sub folder mw3sm26t.default date modified 16/02/2014 sessionstore.bak sessionstore.bak - 20140212...... sessionstore.js

Sub folder date modified 26/09/2014 sessionCheckpoints.json sessionstore.bak sessionstore.js

Don't worry about my query on Thunderbird auto installing. I will find out about that separately.

It sounds like the 1 October 2014 folder would have the latest files, but that's already a couple weeks back so I don't know whether it has anything of use for you. Can you use the details view to see when those were last updated?

Regarding the "Restore Previous Session" being grayed out, that could happen if the previous session was restored automatically, either due to:

• your startup setting (Startup, home page, tabs, and download settings)
• Firefox recovering from a crash during shutdown, or
• a user.js file overriding your normal startup setting (your system info doesn't show the third file, so I think we can rule that out)

It also could happen if Firefox is set to clear all history at shutdown (windows and tabs are part of history) or some external privacy software is removing it. When you backed up your current sessionstore.* files, did they seem up-to-date?

jascher2000 thank you for staying with this.

You asked "When you backed up your current sessionstore.* files, did they seem up-to-date?" I don't understand this Q. I back up of all my files every few weeks but do not back up any one file separately.

I have access to everything I want to have access to and my tabs reopen after each session without a problem. I have checked 'Show my Windows and Tabs from last time' in Startup and it works perfectly.

I would be very happy if 'Restore Previous Session' worked from today onwards, I'm not worried now about historical stuff. When the latest version of Firefox was installed I had problems with Flash Player and after the crash I lost all my Pinned Tabs. That was when I realised 'Restore Previous Session' was not available/greyed out. I have not yet customised Firefox to any great extent as I am waiting for the Session Restore to be back in working order before I start customising.

PS. Firefox remembers history and I clear it every week.

Hi Figgerty, because you have selected 'Show my Windows and Tabs from last time' in Startup, Firefox is restoring the previous session automatically and 'Restore Previous Session' will always be grayed out.

That's because Firefox only tracks one previous session, there's no way to go back to yesterday automatically, and then switch to an earlier session from the day before. Actually, there is an add-on that lets you do that called Session Manager which can store multiple earlier sessions. I haven't tried it myself.

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

Hello jascher2000

So, I have wasted your time for nothing, or have I?

In the event of a FF crash, I thought 'Restore Previous Session' would in fact restore FF to the state before the crash. Which is what I would want to happen. As I have chosen 'Show my Windows and Tabs from last time' in Startup, will this also work after a crash?

On the previous version of Firefox, my Tabs opened after restarting Firefox, but not after a crash. That was when I used the "Restore Previous Session" circle on the bottom of the Home Page to get my Tabs restored.

Is it possible to have my Tabs opened from last time and to have them open after a crash - that was what I thought I was getting!

Firefox should restore automatically after a crash, unless you turn that off. You could check the sessionstore preferences in about:config to make sure.

(1) In a new tab, type or paste about:config in the address bar and press Enter. 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) Make sure the browser.sessionstore.resume_from_crash preference has its default value of true.

If any of the other sessionstore preferences seem suspicious, feel free to ask about them.

Jscher2000

I checked the "browser.sessionstore.resume_from_crash" and the default value is set to True.

I also changed Startup settings to show Home Page on Startup, then closed Firefox and reopened it. Only one tab opened on Startup but I was able to click 'Restore Previous Session' as you said.

The reason I started this question was because I lost all my Tabs, including my Pinned ones when FF and/or Flash Player crashed just after I installed the latest version of Firefox. I was unable to restore them.

I may try out the session-manager Add-On mentioned in your earlier post but I wonder if there are likely to be conflicts.

I am really sorry about the amount of time you have spent in helping me sort out I problem I do not have. At least I now know I do not have a problem.

Thanks again for your help and this question will now be marked as resolved.

Well, I think it's a problem when you lose history that you didn't want to lose. But hopefully it was a one-time occurrence.

That was the reason that I wanted this restore session sorted out before I invested too much time in customising this version of Firefox.

I have also resolved the problem of automatic installing of Mozilla updates by changing the settings in Options, Advanced and Update, to "Check for Updates, but let me decide whether to install them" I usually install all updates but I like to do so at a time convenient to me so this setting is just right for me.

Thanks for all your help. I mean this in the nicest possible way, but I hope we do not need to correspond again for a long time.

Good night