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

Why do 3 instances of Firefox open at the same time?

  • 1 reply
  • 1 has this problem
  • 1 view
  • Last reply by cor-el

more options

Every time I start up Firefox, 3 different instances of Firefox will open at the same time. Do I need to uninstall it and start over? I don't know why this is happening. When I open IE8 only one page opens; but when I open Firefox 3 tabs open at the same time.

Every time I start up Firefox, 3 different instances of Firefox will open at the same time. Do I need to uninstall it and start over? I don't know why this is happening. When I open IE8 only one page opens; but when I open Firefox 3 tabs open at the same time.

All Replies (1)

more options

It is possible that there is a problem with the files sessionstore.js and sessionstore.bak in the Firefox Profile Folder.

Delete the files sessionstore.js and sessionstore.bak in the Firefox Profile Folder.

If you see files sessionstore-##.js with a number in the left part of the name like sessionstore-1.js then delete those as well.
Deleting sessionstore.js will cause App Tabs and Tab Groups to get lost, so you will have to create them again (make a note).

See: