Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in /srv/www/sites/public/starter-projects/vendor/symfony/mailer/Test/TransportFactoryTestCase.php:29 Stack trace: #0 {main} thrown in /srv/www/sites/public/starter-projects/vendor/symfony/mailer/Test/TransportFactoryTestCase.php on line 29