« MODx Parse Error »

MODx encountered the following error while attempting to parse the requested resource:
« PHP Parse Error »
 
PHP error debug
  Error: Only variables should be passed by reference 
  Error type/ Nr.: - 2048 
  File: /home/aubi1co/public_html/assets/snippets/phpthumb/phpThumb.config.php 
  Line: 30 
  Line 30 source: $PHPTHUMB_CONFIG['document_root'] = realpath((getenv('DOCUMENT_ROOT') && preg_match('/^/', preg_quote(realpath(getenv('DOCUMENT_ROOT'))), realpath(__FILE__))) ? getenv('DOCUMENT_ROOT') : str_replace(dirname(@$_SERVER['PHP_SELF']), str_replace(DIRECTORY_SEPARATOR, '/', dirname(__FILE__))));  
 
Parser timing
  MySQL: 0.0082 s(6 Requests)
  PHP: 0.1846 s 
  Total: 0.1928 s