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!

Sykje yn Support

Mij stipescams. Wy sille jo nea freegje in telefoannûmer te beljen, der in sms nei ta te stjoeren of persoanlike gegevens te dielen. Meld fertochte aktiviteit mei de opsje ‘Misbrûk melde’.

Learn More

Dizze konversaasje is argivearre. Stel in nije fraach as jo help nedich hawwe.

I can't open version 4.0 because it says there is already a version open which I can't find to eliminate

  • 1 antwurd
  • 1 hat dit probleem
  • 4 werjeftes
  • Lêste antwurd fan cor-el

more options

I'm on system 10.5.8. Firefox 4.0.1 works on my desktop but won't open on the other user's desktop (although it has been downloaded and dragged to his applications). We get the message "A copy of Firefox is already open. Only one copy of Firefox can be open at a time." Can't find any other copy of Firefox in his space.

I'm on system 10.5.8. Firefox 4.0.1 works on my desktop but won't open on the other user's desktop (although it has been downloaded and dragged to his applications). We get the message "A copy of Firefox is already open. Only one copy of Firefox can be open at a time." Can't find any other copy of Firefox in his space.

Alle antwurden (1)

more options

Check that you still have the profile that is listed as Default=1 in the file profiles.ini

If profiles.ini is there, but the profile is missing then trash the profiles.ini file and let Firefox create a new default profile.