« MODx Parse Error »

MODx encountered the following error while attempting to parse the requested resource:
« PHP Parse Error »
PHP error debug
  Error: Invalid argument supplied for foreach() 
  Error type/ Nr.: Warning - 2 
  File: C:\Program Files\Apache Software Foundation\apache2.2\htdocs\tes\assets\snippets\ditto\classes\ditto.class.inc.php 
  Line: 771 
  Line 771 source: foreach ($modx->documentMap as $null => $document) {  
Parser timing
  MySQL: 0.0020 s(5 Requests)
  PHP: 0.0413 s 
  Total: 0.0433 s 
Error while inserting event log into database: Unknown column 'eventid' in 'field list'