CMS cannot create article in CMS
 

Whenever I create an article it seems to work for about and hour then my entire CMS crashes and I get this error:

Fatal error: Call to undefined function rbs_url_sanity() in forum/includes/functions.php(6811) : eval()'d code on line 62

The only way to get the CMS working again is to delete my articles and have an empty CMS.
How do I fix this?