Fatal error: Uncaught Error: Class 'PhpOffice\PhpSpreadsheet\Calculation\Database\DatabaseAbstract' not found in C:\xampp\htdocs\menejemen-risiko\vendor\phpoffice\phpspreadsheet\src\PhpSpreadsheet\Calculation\Database\DSum.php:8 Stack trace: #0 {main} thrown in C:\xampp\htdocs\menejemen-risiko\vendor\phpoffice\phpspreadsheet\src\PhpSpreadsheet\Calculation\Database\DSum.php on line 8