Fatal error: Uncaught Error: Class "PHP_UML_Output_ExporterXSL" not found in C:\xampp\htdocs\php\pear\PHP\UML\Output\Html\Exporter.php:27 Stack trace: #0 {main} thrown in C:\xampp\htdocs\php\pear\PHP\UML\Output\Html\Exporter.php on line 27