Fatal error: Uncaught Error: Class 'TCPDF' not found in /opt/lampp/htdocs/dhtmlxSuite_v5.1/codebase/grid-pdf-php/gridPdfWrapper.php:3 Stack trace: #0 {main} thrown in /opt/lampp/htdocs/dhtmlxSuite_v5.1/codebase/grid-pdf-php/gridPdfWrapper.php on line 3