Fatal error: Uncaught Error: Class "PhpOffice\PhpSpreadsheet\Writer\Xlsx\WriterPart" not found in C:\Apache24\htdocs\cms_upgrade\vendor\phpoffice\phpspreadsheet\src\PhpSpreadsheet\Writer\Xlsx\Style.php:17 Stack trace: #0 {main} thrown in C:\Apache24\htdocs\cms_upgrade\vendor\phpoffice\phpspreadsheet\src\PhpSpreadsheet\Writer\Xlsx\Style.php on line 17