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

Natao arisiva ity resaka mitohy ity. Mametraha fanontaniana azafady raha mila fanampiana.

Firefox will not open, but computer thinks it IS open

  • 1 valiny
  • 9 manana an'ity olana ity
  • 1 view
  • Valiny farany nomen'i TonyE

more options

I just got a new iMac, and wanted to transfer all my old Firefox info from my old machine. I downloaded the newest version of Firefox, and it seemed to work fine. Then I tried to move my profiles to the new machine (both on same network). Then I don't know what happened. I had to close Firefox for some reason, and when I tried to reopen it was told by my Mac that "A copy of Firefox is already open. Only one copy of Firefox can be open at a time". I checked in Finder to see if I could force-quit Firefox, but according to Finder firefox was NOT running.

I first did a restart of the computer, but when I tried to open Firefox got the same message. Then I threw my Firefox application away and downloaded a new one. No help, same error message.

So how do I convince my Mac that Firefox isn't already running? Help, please!!!

(edited to stop the post from scrolling off to the right)

I just got a new iMac, and wanted to transfer all my old Firefox info from my old machine. I downloaded the newest version of Firefox, and it seemed to work fine. Then I tried to move my profiles to the new machine (both on same network). Then I don't know what happened. I had to close Firefox for some reason, and when I tried to reopen it was told by my Mac that "A copy of Firefox is already open. Only one copy of Firefox can be open at a time". I checked in Finder to see if I could force-quit Firefox, but according to Finder firefox was NOT running. I first did a restart of the computer, but when I tried to open Firefox got the same message. Then I threw my Firefox application away and downloaded a new one. No help, same error message. So how do I convince my Mac that Firefox isn't already running? Help, please!!! ''(edited to stop the post from scrolling off to the right)''

Novain'i TonyE t@

All Replies (1)

more options

For details of how to fix this see this site - http://kb.mozillazine.org/Profile_in_use