Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in /var/www/usonboard.com/vendor/composer/semver/tests/Constraint/MatchAllConstraintTest.php:16 Stack trace: #0 {main} thrown in /var/www/usonboard.com/vendor/composer/semver/tests/Constraint/MatchAllConstraintTest.php on line 16