Fatal error: Uncaught Error: Class 'Symfony\Component\Config\Definition\Builder\VariableNodeDefinition' not found in /home/app/htdocs/ninja/vendor/symfony/config/Definition/Builder/ScalarNodeDefinition.php:21 Stack trace: #0 {main} thrown in /home/app/htdocs/ninja/vendor/symfony/config/Definition/Builder/ScalarNodeDefinition.php on line 21