Fatal error: Uncaught Error: Class 'WP_Upgrader_Skin' not found in E:\www\web\wp-content\plugins\wp-mail-smtp\src\Admin\PluginsInstallSkin.php:11 Stack trace: #0 {main} thrown in E:\www\web\wp-content\plugins\wp-mail-smtp\src\Admin\PluginsInstallSkin.php on line 11