Fatal error: Uncaught Error: Class "PHPMailer\Test\PreSendTestCase" not found in /var/www/html/mun/mailer/phpmailer/test/PHPMailer/ICalTest.php:21 Stack trace: #0 {main} thrown in /var/www/html/mun/mailer/phpmailer/test/PHPMailer/ICalTest.php on line 21