Fatal error: Uncaught Error: Class "App\Install\Service\Package\PackageHandler" not found in C:\xampp\htdocs\SuiteCRM-8.9.2\core\backend\Install\Service\Upgrade\UpgradePackageHandler.php:37 Stack trace: #0 {main} thrown in C:\xampp\htdocs\SuiteCRM-8.9.2\core\backend\Install\Service\Upgrade\UpgradePackageHandler.php on line 37