Fatal error: Uncaught Error: Class 'WPMailSMTP\Admin\PageAbstract' not found in C:\xampp\htdocs\wp-content\plugins\wp-mail-smtp\src\Admin\Pages\SettingsTab.php:16 Stack trace: #0 {main} thrown in C:\xampp\htdocs\wp-content\plugins\wp-mail-smtp\src\Admin\Pages\SettingsTab.php on line 16