Join the AMA (Ask Me Anything) with the Firefox leadership team to celebrate Firefox 20th anniversary and discuss Firefox’s future on Mozilla Connect. Mark your calendar on Thursday, November 14, 18:00 - 20:00 UTC!

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

This thread was archived. Please ask a new question if you need help.

Error message that old firefox is running when starting firefox

  • 1 reply
  • 0 have this problem
  • 1 view
  • Last reply by cor-el

Alvaro Andraca
Alvaro Andraca
more options

Starting today (Apr 30), when trying to open firefox the following message appears:

"Firefox is running, but not responding. The old Firefox process must be closed to open a new window." My options are to close firefox or cancel.

When selecting close firefox, the message will reappear with the same options. I am unable to run.

Steps I have taken: Uninstall Firefox Download latest Install

Message still appears

Starting today (Apr 30), when trying to open firefox the following message appears: "Firefox is running, but not responding. The old Firefox process must be closed to open a new window." My options are to close firefox or cancel. When selecting close firefox, the message will reappear with the same options. I am unable to run. Steps I have taken: Uninstall Firefox Download latest Install Message still appears

All Replies (1)

cor-el
cor-el
  • Moderator
  • Top 10 Contributor
more options

You can check this article.