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

Wannan tattunawa ta zama daɗaɗɗiya. Yi sabuwar tambaya idan ka na bukatar taimako.

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 amsa
  • 1 yana da wannan matsala
  • 2 views
  • Amsa ta ƙarshe daga 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.