Error: Download of swfupload_f9.swf returned response code 404

If you encountered a WordPress Error with returned response code of 404 you’ve come to the right place. This is the common error that was encountered after upgrading to WordPress 2.6 and activating Google Gears. Error: Download of {your domain}/wp-includes/js/swfupload/swfupload_f9.swf returned response code 404 is the exact error message inside your administration panel.

To fix this, you just need to edit gears-manifest.php inside your wp-admin folder and remove the following lines of code:

{ "url" : "../wp-includes/js/tinymce/plugins/media/img/flv_player.swf" },

and

{ "url" : "../wp-includes/js/swfupload/swfupload_f9.swf" },

It’s on line 189 and line 118. That’s it, I hope this helps… 🙂 Enjoy WordPress 2.6