The Reset Firefox feature can fix many issues by restoring Firefox to its factory default state while saving your essential information. Note: This will cause you to lose any Extensions, Open websites, and some Preferences.

To Reset Firefox do the following:

1. Go to Firefox > Help > Troubleshooting Information.
2. Click the "Reset Firefox" button.
3. Firefox will close and reset. After Firefox is done, it will show a window with the information that is imported. Click Finish.
4. Firefox will open with all factory defaults applied.

Further information can be found in the Refresh Firefox - reset add-ons and settings article.

Did this fix your problems? Please report back to us!

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.

• Help > Troubleshooting Information > Profile Directory: Open Containing Folder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

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).

• http://kb.mozillazine.org/Multiple_profile_files_created

HI,

Deleting sessionstore files did not help. But resetting firefox helped. Thanks everyone.

Regards,

Rama

One that worked for me:

If in Windows:

1. Go to Folder Options. In XP it's available in Explorer. In Vista and 7 (possibly 8 as well) it in the Control Panel.
2. Click on the "View" tab. Make sure that in XP, "Show hidden files, folders and drives" is checked. In Vista and 7, make sure the radio button with the above name is marked under the "Hidden files and folders" subheading.
3. Make sure that "Hide protected operating system files" is unchecked.

You'll now be able to see the "Users" folder in Windows Vista and above and "Application Settings" in XP and below on the root part of your C: drive.

In XP, the folder will be "Application Settings/Roaming/Mozilla/Firefox/Profiles". In Windows Vista and above it will be in "Users/user account/AppData/Roaming/Mozilla/Firefox/Profiles".

Go into the profile folder that isn't working and open the "user.js" file in Notepad when Firefox isn't running. Look for the line that says "user_pref("browser.sessionstore.resume_session_once", true);". If it's there as it sits, change "true" to "false".

Save the file and then reopen Firefox to see if it works.

Hi TranceWarp, just a note that it might be easier for many people to modify that setting from inside Firefox using the about:config preferences editor.

Edit: I misread your post, sorry. As noted by cor-el, user.js does need to be edited manually.

If there is a user.js file that sets this pref (and there have been more reports about this) then changing the pref on about:config won't help. Firefox would also disable this pref automatically on each start.