Fatal error: Uncaught Error: Class 'PhpOffice\PhpSpreadsheet\Calculation\Database\DatabaseAbstract' not found in /home/edmedu/www/edmeducation.co.kr/tw-dev/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Calculation/Database/DAverage.php:7 Stack trace: #0 {main} thrown in /home/edmedu/www/edmeducation.co.kr/tw-dev/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Calculation/Database/DAverage.php on line 7