Fatal error: Uncaught Error: Class "PhpOffice\PhpSpreadsheet\Writer\Xls\BIFFwriter" not found in /home/romafi/cofortest/php/php-spreadsheet/src/PhpSpreadsheet/Writer/Xls/Worksheet.php:57 Stack trace: #0 {main} thrown in /home/romafi/cofortest/php/php-spreadsheet/src/PhpSpreadsheet/Writer/Xls/Worksheet.php on line 57