global posts feed

When I test the widget by clicking on the RSS feed button on the widget, I end up with a 404 error.

When I go to: http://omniallinfinitude.com/wp-content/recent-global-posts-feed.php, my Mac says "Error, no associated application can be found".

The Post Indexer is installed, network activated.

I have added to WP_CONFIG.PHP the network activation statement per another support thread.

Any ideas?