Fatal error: Uncaught Error: Class 'PhpOffice\PhpSpreadsheet\Writer\Xls\BIFFwriter' not found in /var/www/app/appregwebservice/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Xls/Worksheet.php:56 Stack trace: #0 {main} thrown in /var/www/app/appregwebservice/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Xls/Worksheet.php on line 56