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Wannan tattunawa ta zama daɗaɗɗiya. Yi sabuwar tambaya idan ka na bukatar taimako.

How do I restore a lost previous session

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When I opened my computer, Firefox had crashed with the bug report window open. Without thinking however, I clicked on the Firefox icon in the toolbar which opened a new session in the homepage instead. When that happened, it didn't give me the option to restore my previous session (the option was grayed out) and hitting "Restart Firefox" in the crash window only opened another new tab at the home screen.

I had a decent number of tabs open that I would have like to keep open and I'm not able to remember all of them so is there a way to retrieve a lost session at this point?

When I opened my computer, Firefox had crashed with the bug report window open. Without thinking however, I clicked on the Firefox icon in the toolbar which opened a new session in the homepage instead. When that happened, it didn't give me the option to restore my previous session (the option was grayed out) and hitting "Restart Firefox" in the crash window only opened another new tab at the home screen. I had a decent number of tabs open that I would have like to keep open and I'm not able to remember all of them so is there a way to retrieve a lost session at this point?

All Replies (12)

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This might help.

Don't delete the files if you need to rescue any data from them, just move them out of the profile folder to some location where Firefox doesn't look for them. You can try to read out their contents using this tool: https://www.jeffersonscher.com/res/scrounger.html

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FredMcD said

This might help. Don't delete the files if you need to rescue any data from them, just move them out of the profile folder to some location where Firefox doesn't look for them. You can try to read out their contents using this tool: https://www.jeffersonscher.com/res/scrounger.html

I'm not sure I understand. I haven't deleted any files nor do I even know what files you're talking about. The website you linked to will probably help but I don't know where to find the specific sessionrestore file. I have found some but they're either from today (one is the session I'm currently using and one is the single homepage that was restored) and the rest that I've found seem to be from June for some reason

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FredMcD said

This might help. Don't delete the files if you need to rescue any data from them, just move them out of the profile folder to some location where Firefox doesn't look for them. You can try to read out their contents using this tool: https://www.jeffersonscher.com/res/scrounger.html

I don't really understand. I haven't deleted any files and I'm even not entirely sure which files you're talking about. I'm guessing you mean the sessionstore files based on the website you've linked to me. I was able to find those in one of the profile folders but the only ones I could find are from today (the single home page, named previous), my current session (named "recovery") and for some reason, a few other folders in the profiles folder from June (I think I was having an issue with Firefox that day and because of that these were never cleared properly or something). Otherwise, I can't find the sessionstore that I'm looking for

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Last reply by Mike 29 minutes ago

Sorry, current forum security sometimes delays the posting of messages. And in turn, we are not notified of those posts.

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FredMcD said

Last reply by Mike 29 minutes ago Sorry, current forum security sometimes delays the posting of messages. And in turn, we are not notified of those posts.

That's alright, I think because of them being delayed, I'm not even able to see my own posts until they are approved so even though it says I replied, there isn't actually any post there at the moment

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Click on the link I posted. I think there are instructions.

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Could you check whether either of these are available (not hidden or grayed out) now:

  • "3-bar" menu button > Restore Previous Session
  • (menu bar) History > Restore Previous Session

If they are missing or grayed, the last session probably was restored. Anything useful when you check either:

  • "3-bar" menu button > Library > History > Recently Closed Windows
  • "Library" toolbar button > History > Recently Closed Windows
  • (menu bar) History > Recently Closed Windows

If that doesn't help...

Firefox creates numerous session history files, but because session history is only for the immediately previous session, it is unfortunately too easy to lose it. Could you start by making a backup of your existing session history files? Here's how:

Do not exit Firefox, or if you closed it, don't re-open it.

(1) To open your profile folder...

If Firefox is still running:

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

  • "3-bar" menu button > "?" Help > 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 "Open Folder" (or "Show in Finder") button.

If Firefox is closed:

Type or paste the following into the Windows Run dialog or the system search box and press Enter to launch Windows Explorer:

%APPDATA%\Mozilla\Firefox\Profiles

In that folder, do you see a semi-randomly-named folder? If so, click into it. If you find multiple such folders, find the one that was most recently updated.

(2) Copy out session history files

In your profile folder, double-click into the sessionstore-backups folder. Save all files here to a safe location such as your Documents folder.

(3) What files did you find?

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

  • recovery.jsonlz4: 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)
  • recovery.baklz4: a backup copy of recovery.jsonlz4
  • previous.jsonlz4: the windows and tabs in your last Firefox session
  • upgrade.jsonlz4-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 you think any of them would have the missing tabs?

To preview the contents of a file, you can drag and drop it onto a tool on my site, then click Scrounge URLs:

https://www.jeffersonscher.com/ffu/scrounger.html

If you don't get a list within 15 seconds, that probably means the script is caught in a loop. You may need to close the tab to avoid a tab crash and then try again in a new tab.

If you get a useful list, use the Save List button to archive it as a web page of clickable links for future reference, in case no other approach is successful.

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FredMcD said

Click on the link I posted. I think there are instructions.

I did. As mentioned, the only two files available there are the one titles "previous" (the single home page tab) and the one titled "recovery" (my current session) so is there any other place I would be able to look?

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jscher2000 said

Could you check whether either of these are available (not hidden or grayed out) now:
  • "3-bar" menu button > Restore Previous Session
  • (menu bar) History > Restore Previous Session

The "3-bar" menu one is grayed out currently and I don't see a Restore Previous session in the history menu

If they are missing or grayed, the last session probably was restored. Anything useful when you check either:
  • "3-bar" menu button > Library > History > Recently Closed Windows
  • "Library" toolbar button > History > Recently Closed Windows
  • (menu bar) History > Recently Closed Windows

Unfortunately no, all those are are windows closed during the current session, none from my previous session

Firefox creates numerous session history files, but because session history is only for the immediately previous session, it is unfortunately too easy to lose it. Could you start by making a backup of your existing session history files? Here's how: ... (3) What files did you find? The kinds of files you may find among your sessionstore files are:
  • recovery.jsonlz4: 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)
  • recovery.baklz4: a backup copy of recovery.jsonlz4
  • previous.jsonlz4: the windows and tabs in your last Firefox session
  • upgrade.jsonlz4-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 you think any of them would have the missing tabs?

I was able to find the files but both Recovery files are from the current session and Previous and Upgrade are both only the single homepage that I would get when opening a fresh session of Firefox and were both created/modified at the same time

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Hi Mike, it's not sounding very hopeful if even your last upgrade snapshot didn't have any tabs in it.

Is everything else normal in your Firefox, or is it possible that this is a new profile? If a profile is locked by a crash or external software, it's possible that Firefox would create a new one.

If you haven't already, could you close out of Firefox and do a normal Windows shutdown and restart to complete any pending updates and release any file locks.

If Firefox again starts up without your data, could you check whether your stuff is available in a different profile, as follows:

Profile Manager Page

Inside Firefox, type or paste about:profiles in the address bar and press Enter/Return to load it.

This page should list at least one profile and could list many. (Each profile has two folders and one or more buttons. Do not use any Remove buttons!)

The profile that Firefox is currently using will have this:

This is the profile in use and it cannot be deleted.

Do you have another profile listed on this page? If so, you can check whether it is the one you were using recently by clicking its Launch profile in new browser button.

If it isn't what you want, simply close that new window.

If it IS what you want, back on the about:profiles page, click the Set as default profile button for that profile so Firefox uses it automatically at the next startup.


Otherwise, perhaps an unerase program like Recuva can find a recent recovery.jsonlz4 file from the right time period. Those often are unusable because they can't be recovered perfectly, but you never know:

https://www.ccleaner.com/recuva

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jscher2000 said

Is everything else normal in your Firefox, or is it possible that this is a new profile? If a profile is locked by a crash or external software, it's possible that Firefox would create a new one. ... Profile Manager Page Inside Firefox, type or paste about:profiles in the address bar and press Enter/Return to load it. This page should list at least one profile and could list many. (Each profile has two folders and one or more buttons. Do not use any Remove buttons!) The profile that Firefox is currently using will have this: This is the profile in use and it cannot be deleted. Do you have another profile listed on this page? If so, you can check whether it is the one you were using recently by clicking its Launch profile in new browser button.

There are 6 other profiles besides my primary one, all named default-release (default-release, default-release-1, etc.). These seem to connect to the additional profiles I found in the profiles folder. Unfortunately, they are all mostly the same couple of tabs and seem to be profiles that were inadvertently created because of an issue I was having back in June

Otherwise, perhaps an unerase program like Recuva can find a recent recovery.jsonlz4 file from the right time period. Those often are unusable because they can't be recovered perfectly, but you never know: https://www.ccleaner.com/recuva

This program seems useful in general, unfortunately, while I was able to find a couple of files with it that probably would have worked, and had data and were even in "Excellent" condition with nothing overwriting their data, for some reason they aren't able to be read by the jeffersonscher site. One is a sessionCheckpoints file so maybe that just can't be read properly but the "previous" I found must have had a slight change that allowed it to hold it's data but not be recognizable by the site and unfortunately I don't even know where to begin with potentially fixing it if that's even possible.

I appreciate the help here. I've been trying to remember all of the lost tabs and I think I have at least most of the important ones back so while it would have been nice to get everything back through Firefox itself to be certain, it wasn't a total loss.

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Hi Mike, at the end of the day, we do have cases of S*** Happens that we can't solve. If you don't already have Firefox set to restore your previous session automatically -- first checkbox on the Options page -- you might consider it. It has saved me so many times (even if it tests my patience on some days).