Fatal error: Uncaught Error: Interface 'PhpOffice\PhpSpreadsheet\Writer\IWriter' not found in /var/www/app/appregwebservice/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/BaseWriter.php:5 Stack trace: #0 {main} thrown in /var/www/app/appregwebservice/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/BaseWriter.php on line 5