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Tried to upgrade a IBook G4 to FireFox 4.0 and could not make it work, is 4.0 not supported on this older machine?


Per instructions I tried to upgrade to FireFox 4.0 on my older iBook G4 and would not open. The FireFox logo had a white circle imposed on it. I was really stuck with the older version gone, and the newer one would not work. I managed to copy an older version of FireFox from another machine. Funny thing is that after loading the copy, I was still asked to upgrade to 4.0. All of this was very frustrating.

Additional System Details

Installed Plug-ins

  • Gecko default plugin
  • Netscape Navigator Default Plug-in
  • Runs Java applets using the latest installed versions of Java. For more information: Java Embedding Plugin. Run version test: Java Information.
  • The QuickTime Plugin allows you to view a wide variety of multimedia content in web pages. For more information, visit the QuickTime Web site.
  • Shockwave Flash 10.1 r85
  • The Flip4Mac WMV Plugin allows you to view Windows Media content using QuickTime.
  • Coupons Inc Bricks Safari Plugin
  • iPhoto6
  • Java 1.3.1 Plug-in
  • Simplifies the uploading of photo files.
  • Provides support for Digital Rights Management
  • Shockwave Flash 6.0 r47
  • Java 1.3.1 Plug-in (CFM)
  • Macromedia Shockwave for Director Netscape plug-in, version 10.1.1


  • User Agent: Mozilla/5.0 (Macintosh; U; PPC Mac OS X 10.4; en-US; rv: Gecko/20100202 Firefox/3.5.8

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  • Moderator
1041 solutions 8840 answers

Helpful Reply

Firefox 4 requires at least OS X 10.5 and an Intel Mac. There is a third party version of Firefox 4 that runs on OS X 10.4/10.5 and PPC Macs, for details see http://www.floodgap.com/software/tenfourfox

The latest official version to run on OS X 10.4 is Firefox 3.6.16 available from http://www.mozilla.com/en-US/firefox/all-older.html

Mozilla are working to prevent Mac users with non-compatible systems from getting the notification about Firefox 4, and also not displaying the "Download Firefox 4" button on http://www.mozilla.com