Fatal error: Uncaught Error: Class "Symfony\Component\Config\Definition\Exception\Exception" not found in /home/.sites/site4/wwwroot/web/4.0/ui/vendor/symfony/config/Definition/Exception/UnsetKeyException.php:20 Stack trace: #0 {main} thrown in /home/.sites/site4/wwwroot/web/4.0/ui/vendor/symfony/config/Definition/Exception/UnsetKeyException.php on line 20