Windows 10 will reach EOS (end of support) on October 14, 2025. For more information, see this article.

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 does not even open

  • 7 replies
  • 12 have this problem
  • 1 view
  • Last reply by cor-el

more options

When I start Firefox, I can see the "Working circle" for a few seconds and than nothing... I checked in the Task Manager and saw Firefox coming up and disappearing immediately.

Firefox used to work perfectly just before...

When I start Firefox, I can see the "Working circle" for a few seconds and than nothing... I checked in the Task Manager and saw Firefox coming up and disappearing immediately. Firefox used to work perfectly just before...

All Replies (7)

more options

Try the procedures in the Firefox won't start - find solutions article.

more options

Start Firefox in Use Troubleshoot Mode in Firefox to check if one of your add-ons is causing your problem (switch to the DEFAULT theme: Tools > Add-ons > Themes).

See Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems and Troubleshoot issues with plugins like Flash or Java to fix common Firefox problems


A possible cause is security software (firewall) that blocks or restricts Firefox without informing you about that, possibly after detecting changes (update) to the Firefox program.

Remove all rules for Firefox from the permissions list in the firewall and let your firewall ask again for permission to get full unrestricted access to internet for Firefox.

See Server Not Found - Troubleshoot connection problems and Configure firewalls so that Firefox can access the Internet and http://kb.mozillazine.org/Firewalls

more options

Thank you for you answer. But Firefox does not start even in Safe mode...

Regards.

more options

I couldn't try any of them since I cannot open Firefox ! Not even is Safe mode... But I created a new profile... Not working...

Thanks anyway.

more options

Try right-clicking on the Mozilla icon and "run as Administrator".

more options

I tried this too... Same result : Nothing !

Thank you anyway

more options

Did you check your security software ?