Avatar for Username

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

Echekwara usoro a. Biko jụọ ajụjụ ọhụrụ ma ọ bụrụ na ị chọrọ enyemaka.

Error message - "A copy of firefox is already open. Only one copy of firefox can be open at a time" but there is no firefox window open.

  • 1 nzaghachinzaghachi
  • 1 nwere nsogbu anwere nsogbu a
  • 3 views
  • Nzaghachi ikpeazụ nke Shadow110

singer.kirsten
singer.kirsten
more options

Computer crashed suddenly (Macbook Pro). I was able to restart all programs except Firefox. I unistalled and re-downloaded FF, but when I try to open the application, I receive the error "A copy of firefox is already open. Only one copy of firefox can be open at a time". However, there are no other copies of FF open since technically it was uninstalled.

Computer crashed suddenly (Macbook Pro). I was able to restart all programs except Firefox. I unistalled and re-downloaded FF, but when I try to open the application, I receive the error "A copy of firefox is already open. Only one copy of firefox can be open at a time". However, there are no other copies of FF open since technically it was uninstalled.

All Replies (1)

Shadow110
Shadow110
more options

https://support.mozilla.org/en-US/kb/firefox-already-running-not-responding?redirectlocale=en-US&redirectslug=Firefox+is+already+running+but+is+not+responding

uninstall Firefox. Then Delete the Mozilla Firefox Folders in C:\Program Files and C:\Program Files(x86). DO MAC EQUIVALENT Note: your Firefox Profile is saved. But you should make a back up before you do :

Reinstall with Current Release Firefox 57.0.3 with a Full Version Installer

Please let us know if this solved your issue or if need further assistance.