Fatal error: Uncaught Error: Class "PhpOffice\PhpSpreadsheet\Writer\Xlsx\WriterPart" not found in D:\xampp\htdocs\vendor\phpoffice\phpspreadsheet\Writer\Xlsx\ContentTypes.php:13 Stack trace: #0 {main} thrown in D:\xampp\htdocs\vendor\phpoffice\phpspreadsheet\Writer\Xlsx\ContentTypes.php on line 13