Where did you install Firefox from? Help Mozilla uncover 3rd party websites that offer problematic Firefox installation by taking part in our campaign. There will be swag, and you'll be featured in our blog if you manage to report at least 10 valid reports!

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

Lolu chungechunge lwabekwa kunqolobane. Uyacelwa ubuze umbuzo omusha uma udinga usizo.

will not boot up

  • 1 baphendule
  • 1 inale nkinga
  • 12 views
  • Igcine ukuphendulwa ngu cor-el

tom_baltezor
tom_baltezor
more options

When trying to open firefox the following message appears.

Firefox is already running, but not responding. The old Firefox process must be closed to open a new window. If I pic Close Firefox the error message goes away but comes back. I've tried uninstalling and reinstalling with and without resetting to default but no help. Same issue appears.

When trying to open firefox the following message appears. Firefox is already running, but not responding. The old Firefox process must be closed to open a new window. If I pic Close Firefox the error message goes away but comes back. I've tried uninstalling and reinstalling with and without resetting to default but no help. Same issue appears.
Ama-screenshot ananyekiwe

All Replies (1)

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

Try to delete parent.lock in the profile folder.

Location used for the main profile that keeps your personal data.

  • C:\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles\<profile>

You can create a new profile as a quick test to see if your current profile is causing the problem.

See "Creating a profile":

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.