Fatal error: Uncaught Error: Class "Theme" not found in /var/www/html/upload/PhpSpreadsheet-master/vendor/mitoteam/jpgraph/src/lib/themes/PastelTheme.class.php:6 Stack trace: #0 {main} thrown in /var/www/html/upload/PhpSpreadsheet-master/vendor/mitoteam/jpgraph/src/lib/themes/PastelTheme.class.php on line 6