Fatal error: Uncaught Error: Class "WPMailSMTP\ConnectionsManager" not found in /var/www/html/wp-content/plugins/wp-mail-smtp-pro/src/Pro/ConnectionsManager.php:16 Stack trace: #0 {main} thrown in /var/www/html/wp-content/plugins/wp-mail-smtp-pro/src/Pro/ConnectionsManager.php on line 16