Fatal error: Uncaught Error: Class 'PhpOffice\PhpSpreadsheet\Writer\Xlsx\WriterPart' not found in C:\Web\htdocs\vendor-copia\phpoffice\phpspreadsheet\src\PhpSpreadsheet\Writer\Xlsx\Theme.php:8 Stack trace: #0 {main} thrown in C:\Web\htdocs\vendor-copia\phpoffice\phpspreadsheet\src\PhpSpreadsheet\Writer\Xlsx\Theme.php on line 8