Fatal error: Uncaught Error: Class "PhpOffice\PhpSpreadsheet\Calculation\Database\DatabaseAbstract" not found in C:\Apache24\htdocs\cms_upgrade\vendor\phpoffice\phpspreadsheet\src\PhpSpreadsheet\Calculation\Database\DSum.php:7 Stack trace: #0 {main} thrown in C:\Apache24\htdocs\cms_upgrade\vendor\phpoffice\phpspreadsheet\src\PhpSpreadsheet\Calculation\Database\DSum.php on line 7