Fatal error: Uncaught Error: Class "PHPUnit\Framework\Constraint\Constraint" not found in D:\xampp\htdocs\dropifypro\vendor\symfony\http-foundation\Test\Constraint\ResponseHasHeader.php:17 Stack trace: #0 {main} thrown in D:\xampp\htdocs\dropifypro\vendor\symfony\http-foundation\Test\Constraint\ResponseHasHeader.php on line 17