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

Error - Thunderbird app will not open. "Thunderbird is already running, but is not responding." (win10)

  • 1 phendula
  • 3 inale ngxaki
  • 4 views
  • Impendulo yokugqibela ngu Wayne Mery

more options

Thunderbird will not open. the error message is: "Thunderbird is already running, but is not responding. The old Thunderbird process must be closed to open a new window." Pressed the "Close Thunderbird" button, but no response. Checked Task Manager and ended the Thunderbird application...still no change. Uninstalled Thunderbird and downloaded .exe file and installed...still the same error message. Rebooted the computer...still not change. Can you please assist with this problem. Thankyou I

Thunderbird will not open. the error message is: "Thunderbird is already running, but is not responding. The old Thunderbird process must be closed to open a new window." Pressed the "Close Thunderbird" button, but no response. Checked Task Manager and ended the Thunderbird application...still no change. Uninstalled Thunderbird and downloaded .exe file and installed...still the same error message. Rebooted the computer...still not change. Can you please assist with this problem. Thankyou I

Ilungisiwe ngu Wayne Mery

All Replies (1)

more options

Does problem go away?