Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in /home/admin2bannerworl/public_html/admin2.bannerworld.co.uk/vendor/sebastian/environment/tests/OperatingSystemTest.php:17 Stack trace: #0 {main} thrown in /home/admin2bannerworl/public_html/admin2.bannerworld.co.uk/vendor/sebastian/environment/tests/OperatingSystemTest.php on line 17