« MODx Parse Error »

MODx encountered the following error while attempting to parse the requested resource:
« PHP Parse Error »
 
PHP error debug
  Error: mysql_fetch_assoc(): supplied argument is not a valid MySQL result resource 
  Error type/ Nr.: Warning - 2 
  File: /data/www/assets/snippets/course_info/courseinfo.php 
  Line: 331 
  Line 331 source: $row_cross2 = mysql_fetch_assoc($result_cross2);  
 
Parser timing
  MySQL: 0.0085 s(44 Requests)
  PHP: 0.4349 s 
  Total: 0.4433 s