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

Firefox says only one "copy" can run at a time

  • 1 reply
  • 1 has this problem
  • 1 view
  • Last reply by Andrew

more options

I have 2 user accounts on my Mac, only one of which I really use. For some reason, Firefox now refuses to open in that user, saying that there's already a "copy" of Firefox open and that I can't have multiple copies running. (Firefox works fine when I'm on the other user, but it doesn't have all my bookmarks, passwords, etc... not to mention I can't access the non-Firefox files I want.) How do I close or get rid of the extra copy, so I can use Firefox in the other user account? Quitting the app doesn't do it.

I have 2 user accounts on my Mac, only one of which I really use. For some reason, Firefox now refuses to open in that user, saying that there's already a "copy" of Firefox open and that I can't have multiple copies running. (Firefox works fine when I'm on the other user, but it doesn't have all my bookmarks, passwords, etc... not to mention I can't access the non-Firefox files I want.) How do I close or get rid of the extra copy, so I can use Firefox in the other user account? Quitting the app doesn't do it.

All Replies (1)

more options