« MODx Parse Error »

MODx encountered the following error while attempting to parse the requested resource:
« PHP Parse Error »
 
PHP error debug
  Error: Non-static method ditto::getAuthor() should not be called statically 
  Error type/ Nr.: - 2048 
  File: /var/www/archeia.com/assets/snippets/ditto/formats/rss.format.inc.php 
  Line: 101 
  Line 101 source: return htmlspecialchars(html_entity_decode(ditto::getAuthor($resource['createdby']), ENT_QUOTES));  
 
Parser timing
  MySQL: 0.0009 s(5 Requests)
  PHP: 0.0046 s 
  Total: 0.0055 s