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I think my previous session got overwritten by a new one. Is it possible to get back my older session?

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It happened today. I even tried to restore the previous.js to an earlier point (back to 07/05/2016 version) and then I renamed it to sessionstore.js but it still opens the new session whenever I open Mozilla Firefox. I don't know what I'm doing wrong and it's driving me off the wall.

It happened today. I even tried to restore the previous.js to an earlier point (back to 07/05/2016 version) and then I renamed it to sessionstore.js but it still opens the new session whenever I open Mozilla Firefox. I don't know what I'm doing wrong and it's driving me off the wall.

Modified by david-chen

All Replies (14)

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hi, please make sure that you rename & put the file into the profile folder while all instances of firefox are closed.

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Thank you for your response. I actually forgot to do that the first time which I'm guessing the reason why my older previous session got overwritten by a new one. Now, when I try to do it again properly it still doesn't restore my older session.

(Just for the record, I had about 1,900 tabs in the old session. Yes, really lol)

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Did you back up everything in sessionstore-backups for safekeeping?

If you installed the 47.0.1 update last week, you could consider rolling back to that file. It should have a name similar to:

upgrade.js-20160623154057

Its internal format is the same as sessionstore.js, recovery.js, etc., and can be swapped for sessionstore.js in a similar fashion.

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You guys are talking about rolling back to a previous session. I never heard of session store or recovery.js. Please help. I only want to restore 10 tabs.

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Hi budha54, you jumped into the middle of a thread instead of posting a new question, so I suggest starting at the beginning.

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

If Firefox is still up, check the History menu for "Restore Previous Session" and, if it's not grayed out, try that.

Then check the History menu for a list of closed tabs from that window and other windows that were closed that you can re-open. Anything promising?

If that doesn't help, let's back up a few files. Here's how:

(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 > "?" 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.

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, scroll down and double-click into the sessionstore-backups folder. Save all files here to a safe location, such as your Documents folder. If not too much time has passed, we may be able to use them to recover your lost tabs.

(3) What files did you find?

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)
  • recovery.bak: a backup copy of 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 you think any of them would have the missing tabs?

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

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Thank you for responding jscher2000.

I had closed and reopened because an app changed my home page preference and unchecked restore previous session.  I was pissed.

I could not find semi randomly named folder. I dont know what that is. but I would like to find that session history files you spoke of. I did open session store and found the js files. They are from today. My only hope to get some of my tabs back seems to be the js file from the last update about 5days ago. But I dont know how to activate it.

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Hi budha54, to try swapping in a session history file from your backup folder so Firefox will load it, the standard "manual swap" method is as follows (assuming Firefox is still running):

(1) From inside 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. This should launch a Windows Explorer window listing the various files and folders in your profile.

(2) Leaving that window open, switch back to Firefox and Exit, either:

  • "3-bar" menu button > "power" button
  • (menu bar) File > Exit

Pause while Firefox finishes its cleanup -- these changes should occur:

  • recovery.js is moved from the sessionstore-backups folder to the main level of the profile folder and renamed to sessionstore.js
  • recovery.bak is deleted from sessionstore-backups

(3) Once Firefox has stopped updating those files, while viewing the main level of the profile folder, rename sessionstore.js to sessionstore.old

(4) Copy in the other file you want to restore, and rename it to sessionstore.js -- after the rename, Windows should show it right next to sessionstore.old in alphabetical order

(5) Start Firefox and it should read the swapped in sessionstore.js and restore whatever was in the substitute file; if you do not have Firefox set to restore your previous windows and tabs automatically, use History > Restore Previous Session

Any luck?

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Hi JScher2000, WHat is the purpose of putting a file on the clip board? Also, will an update file in sessionstore,backups automatically be read by FF for startup. Why change the other one to old. WHy not just delete it. Sorry for all the questions but I dont understand and I dont want to end up in worse trouble than Im already in.

Doesnt sync have a history somewhere,

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budha54 said

WHat is the purpose of putting a file on the clip board?

The clipboard is the mechanism used to copy/paste. When you copy, the file is duplicated to the clipboard, and when you paste, it is copied out of the clipboard to wherever you paste. But I'm not sure how that factors in here.

Also, will an update file in sessionstore,backups automatically be read by FF for startup.

Sometimes. Firefox will look for sessionstore.js first. If it's missing, it will look for recovery.js. If that is missing, it will look for recovery.bak. I don't remember what happens if that is missing.

Why change the other one to old. WHy not just delete it.

In case you decide you want those later tabs back.

Doesnt sync have a history somewhere,

No, Sync stores the last set of data you sync'd and has no way to roll back.

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You said --- 4) Copy in the other file you want to restore, and rename it to sessionstore.js

I asked why copy this file --- you said

it is copied out of the clipboard to wherever you paste. But I'm not sure how that factors in here.

My answer - me neither!!

I asked if the update file will load from sessionbackup. You seem to be unsure, at best you said sometimes. you said: Sometimes. Firefox will look for sessionstore.js first. If it's missing, it will look for recovery.js. If that is missing, it will look for recovery.bak. I don't remember what happens if that is missing.

Well that just about says it all. this is not the way. Im confused and getting frustrated that is is so difficult to locate and bring back a previous session. ppl in the forum are given advice as to how to restore 500 tabs. There must be a way to bring back 10 tabs.

I will keep asking for a definitive procedure.

also, do I have to manually sync. I thought it happened automatically.

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anyway I tried it the best i could. It didnt make a diff. Any other ways???

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So just to recap:

  • After Firefox shut down and created sessionstore.js, you renamed the file to sessionstore.old
  • You copied the upgrade...js file into the profile folder and renamed it to sessionstore.js
  • Then you started Firefox and, if Firefox didn't restore the old session automatically, you used the History menu to Restore Previous Session

And what tabs did you get from that?

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restore previous session in history doesnt click. I only get the new previous session. Also, I notice the update file I renamed, disappears from the profile folder until I close ff. But the renamed .old file remains. Whats going on -- uf

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Hi budha54, when Firefox starts up, it reads sessionstore.js, uses that to create files in sessionstore-backups, and then deletes sessionstore.js. That is normal.

Did the History menu list any closed windows you could re-open? Or closed tabs?

If having Firefox read/restore that old file didn't give you the the tabs you want, are there any other files you could try? If not, I think you're out of luck.