Fatal error: Uncaught Error: Class 'TreeDataItem' not found in /opt/lampp/htdocs/dhtmlxSuite_v5.1/samples/dhtmlxTreeView/common/connector/filesystem_item.php:7 Stack trace: #0 {main} thrown in /opt/lampp/htdocs/dhtmlxSuite_v5.1/samples/dhtmlxTreeView/common/connector/filesystem_item.php on line 7