Fatal error: Uncaught Error: Class 'PhpOffice\PhpSpreadsheet\Writer\Xls\BIFFwriter' not found in /home/rfslogis/public_html/php/PhpSpreadsheet-master/src/PhpSpreadsheet/Writer/Xls/Worksheet.php:56 Stack trace: #0 {main} thrown in /home/rfslogis/public_html/php/PhpSpreadsheet-master/src/PhpSpreadsheet/Writer/Xls/Worksheet.php on line 56