Fatal error: Uncaught Error: Class 'Whoops\Handler\Handler' not found in /var/www/html/test-project/my-app/vendor/filp/whoops/src/Whoops/Handler/PrettyPageHandler.php:18 Stack trace: #0 {main} thrown in /var/www/html/test-project/my-app/vendor/filp/whoops/src/Whoops/Handler/PrettyPageHandler.php on line 18