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

Trying to open Firefox today I get the message: A copy of Firefox is already open. Only one copy of Firefox can be open at a time. 'm stuck!

  • 5 ŋuɖoɖowo
  • 1 masɔmasɔ sia le esi
  • 2 views
  • Nuɖoɖo mlɔetɔ FredMcD

more options

I can't access Firefox. Get message: A copy of Firefox is already open. Only one copy of Firefox can be open at a time.

Firefox is not open and I need it!

I can't access Firefox. Get message: A copy of Firefox is already open. Only one copy of Firefox can be open at a time. Firefox is not open and I need it!

Ŋuɖoɖo si wotia

Macs: Make sure you install Firefox properly and that you do not run Firefox from within the DMG (Disk Images) file. https://support.mozilla.org/en-US/kb/how-download-and-install-firefox-mac

Xle ŋuɖoɖo sia le goya me 👍 0

All Replies (5)

more options
more options

iMac OS 11.3.1 Can't identify FF version as can't open it! Can't find FF in library or app support so can't find profile Really stuck.

more options

Ɖɔɖɔɖo si wotia

Macs: Make sure you install Firefox properly and that you do not run Firefox from within the DMG (Disk Images) file. https://support.mozilla.org/en-US/kb/how-download-and-install-firefox-mac

more options

Thank you so much! I didn't quite understand everything but by some magic it worked!! And Firefox is back with me and all seems to be in order.

more options

Glad to help. Safe Surfing.