Fatal error: Uncaught Error: Interface 'WPMailSMTP\Providers\MailerInterface' not found in C:\xampp\htdocs\wp-content\plugins\wp-mail-smtp\src\Providers\MailerAbstract.php:18 Stack trace: #0 {main} thrown in C:\xampp\htdocs\wp-content\plugins\wp-mail-smtp\src\Providers\MailerAbstract.php on line 18