Fatal error: Uncaught Error: Class "PHPUnit\Framework\Constraint\Constraint" not found in /home2/natalnin/public_html/testone.natalnine.com/vendor/symfony/mime/Test/Constraint/EmailHasHeader.php:17 Stack trace: #0 {main} thrown in /home2/natalnin/public_html/testone.natalnine.com/vendor/symfony/mime/Test/Constraint/EmailHasHeader.php on line 17