This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Restore Previous Session "grayed out" in history? I know I had a previous session

more options

i was in the middle of doing research on the internet when Windows 7 all of a sudden took my computer down and said it was installing updates. I had no warning whatsoever. I don't know if this is why I am having this problem or not. But, when windows came up, I went to "Restore Last Session" in History as I always do when I suffer a crash and lo-and-behold, "Restore Last Session" is 'grayed-out', for lack of a better term. The option is there, but because it is 'greyed out' I cannot select it. I do have a sessionstore.bak and sessionstore.js file, along with, for some strange reason, a sessionstore-2 file in the following path Computer>Acer(C:)>Users>Acer>AppData>Roaming>Mozilla>Firefox>Profiles>lkhys26m.default. I don't know if this matters or not, but technically both the sessionstore.js and sessionstore.bak files do not have file extensions on them. In other words, no .js or .bak, as I've listed them here but under "type" in the directory listing, they are indicated as such - a javascript file and a bak file. I cannot find any sessionstore files anywhere else. I have always had Firefox to open to the Google home page upon launching because I really don't want my browser opening a bunch of tabs from a previous session everytime I launch Firefox. However this fact has never prevented me from being able to use "Restore Last Session" in History after a crash or forced reboot. All of my History is still intact, nothing missing.

So, why is my "Restore Last Session" option in History all of a sudden 'grayed out' and I can't click it? Thank You in advance for your time and attention.

i was in the middle of doing research on the internet when Windows 7 all of a sudden took my computer down and said it was installing updates. I had no warning whatsoever. I don't know if this is why I am having this problem or not. But, when windows came up, I went to "Restore Last Session" in History as I always do when I suffer a crash and lo-and-behold, "Restore Last Session" is 'grayed-out', for lack of a better term. The option is there, but because it is 'greyed out' I cannot select it. I do have a sessionstore.bak and sessionstore.js file, along with, for some strange reason, a sessionstore-2 file in the following path Computer>Acer(C:)>Users>Acer>AppData>Roaming>Mozilla>Firefox>Profiles>lkhys26m.default. I don't know if this matters or not, but technically both the sessionstore.js and sessionstore.bak files do not have file extensions on them. In other words, no .js or .bak, as I've listed them here but under "type" in the directory listing, they are indicated as such - a javascript file and a bak file. I cannot find any sessionstore files anywhere else. I have always had Firefox to open to the Google home page upon launching because I really don't want my browser opening a bunch of tabs from a previous session everytime I launch Firefox. However this fact has never prevented me from being able to use "Restore Last Session" in History after a crash or forced reboot. All of my History is still intact, nothing missing. So, why is my "Restore Last Session" option in History all of a sudden 'grayed out' and I can't click it? Thank You in advance for your time and attention.

All Replies (9)

more options

Maybe you were in private browsing mode at the end of your last session?

more options

You can try to rename the numbered sessionstore-##.js to sessionstore.js to see if that brings back that session, assuming that the file has a time stamp from around that time.

more options

OK, I hate to sound stupid, but what is "private browsing mode" and how does what enter that mode? Thank you.

more options

For information about Firefox "Private Browsing" mode, see:

more options

OK, I looked over the private browsing information Alice Wyman provided below. It seems quite unlikely I was in private browsing. I check the information under tools>options to make sure private browsing wasn't somehow set to come on automatically, and I never intentionally did a "start private browsing" from the tools drop down. Although it is theoretically possible I somehow doubt the chance I hit the quick-key sequence by accident and started a private browsing session.

more options

I tried that. Thanks. But, it did not work.

more options

If the history is intact like you wrote in your first then Private Browsing mode is not very likely.

If you use cleanup software like CCleaner then check the settings for the Firefox application.


You can check for problems with the sessionstore.js and sessionstore.bak files in the Firefox Profile Folder that store session data.

Delete the sessionstore.js file and possible sessionstore-##.js files with a number and sessionstore.bak in the Firefox Profile Folder.

Deleting sessionstore.js will cause App Tabs and Tab Groups and open and closed (undo) tabs to get lost, so you will have to create them again (make a note or bookmark them).

Modified by cor-el

more options

I've been struggling with this too. I don't have Mozilla Home open as my first page, so my work-around is to type "about:home" in the address bar, enter, and then I can restore last session from there. You must close program through file/exit if you want to recover all your windows. You can use red close button if you only have one window open (all tabs in one window).

This may be how Firefox is deliberately configured now. Or, there may be a hanging thread in RAM: The "restore previous session" will appear in history drop down menu for one instance after a system reboot.

Modified by Dougo

more options

Locking this thread as Firefox has changed since this thread was started back in December.