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

Natao arisiva ity resaka mitohy ity. Mametraha fanontaniana azafady raha mila fanampiana.

4.0 doesn't work with Mac OS X 10.4.11 --> how can I downgrade?

  • 1 valiny
  • 24 manana an'ity olana ity
  • 14 views
  • Valiny farany nomen'i peterroberts

more options

After upgrading to 4.0, I get the following error when trying to open Firefox: "You cannot use the application "Firefox" with this version of Mac OS X."

I am running Mac OS X 10.4.11 on an older laptop.

How can I revert to 3.6.*? I can't find any website to provide this version...

After upgrading to 4.0, I get the following error when trying to open Firefox: "You cannot use the application "Firefox" with this version of Mac OS X." I am running Mac OS X 10.4.11 on an older laptop. How can I revert to 3.6.*? I can't find any website to provide this version...

All Replies (2)

more options

Similar problem - I run Mac OS X 10.4.11 on an iMac and on trying to open Firefox after updating to version 4 this morning get message 'application Firefox cannot be launched -10661'

more options