Believe I have configured Feedapi properly, but am trying to run conversion script on site:

http://test.pflogging.com/leech2feedapi.php

When I do that, I get the following error:

Fatal error: Call to undefined function file_scan_directory() in /home/pfloggin/domains/test.pflogging.com/public_html/includes/common.inc on line 2788

I am not familiar with PHP, and am not able to determine if this is a configuration problem or a bug. I have searched the forums and issue log, and cannot find anything that seems relevant to this situation. Any clues as to what might be occurring? Since I have a significant amount of prior 'leeched' content, much of it linked from other self-generated content, I am really hopeful to be able to use the script, and appreciate efforts to provide that support.