Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in /home/matrixweb/public_html/whmcs2022/whmcs/vendor/symfony/http-foundation/Tests/ResponseHeaderBagTest.php:21 Stack trace: #0 {main} thrown in /home/matrixweb/public_html/whmcs2022/whmcs/vendor/symfony/http-foundation/Tests/ResponseHeaderBagTest.php on line 21