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 wont open as it says its already running but processes are clear

  • 5 replies
  • 3 have this problem
  • 2 views
  • Last reply by FredMcD

more options

Error message : Firefox is already running, but is not responding. The old Firefox process must be closed to open a new window. the process list has no firefox in it i have uninstalled re installed rebooted and still this persists Any ideas ?

Error message : Firefox is already running, but is not responding. The old Firefox process must be closed to open a new window. the process list has no firefox in it i have uninstalled re installed rebooted and still this persists Any ideas ?

All Replies (5)

more options

after you click to close firefox i also get a message : Your Firefox profile cannot be loaded. It may be missing or inaccessible. I'm on windows 10 if that helps too

more options

If you're having trouble with your profile as well, check the instructions in http://kb.mozillazine.org/Profile_in_use regarding access rights and the lock file.

more options

Do you have the Firefox icon on your quick launch? Right click on it, and select Open New Window. Sometimes this works. If it opens, close it by Menu > File > Exit.


This is not a cure but will make it easier if Firefox locks up in Windows. https://support.mozilla.org/questions/997866 {web link}

more options

it just doesnt open says its already open i have deleted program all cookies histories etc re installed and it still says Firefox is already running, but is not responding. The old Firefox process must be closed to open a new window ?

more options

Do the above, but choose New Tab