Thread:Project:Support desk/ Warning: escapeshellarg() has been disabled for security reasons

MediaWiki 1.16.0 PHP 	5.3.6 (cgi-fcgi) Database 5.1.56-log MySQL

http://www.nifrpg.net/wiki/index.php?title=Main_Page

Whenever we try to upload an image, we get this error: Warning: escapeshellarg has been disabled for security reasons in /*****/*****/public_html/*****/includes/GlobalFunctions.php on line 1473 and the image doesn't upload. In place of where the image should appear, the following is there instead: Error creating thumbnail: Unable to run external programs in safe mode. How do we fix this please?