There is a PHP error that has occured, however it is not being displayed. We need to see it in order to troubleshoot what is wrong. You can either turn the php error reporting / display_error on, or you can check the PHP error log.

TO ENABLE PHP ERROR REPORTING:
Make sure your PHP display error or error notification/reporting is turned on.
Use this wiki documentation page for instructions:
http://wiki.datafeedfile.com//wikka.php?wakka=DFFPhpErrorReporting

TO CHECK PHP ERROR LOG:
If you are using a shared hosting account, you should be able to find PHP error log icon / link within your hosting account control panel.
If not you need to find out where your PHP error log location is. You can find out by running phpinfo() function and checking the error_log setting for the location of your error log file. You can also view your php configuration file (php.ini) and check your setting for error_log to check for the file location.