Fatal error: Uncaught Error: Class 'Symfony\Component\DependencyInjection\Definition' not found in /home/app/htdocs/ninja/vendor/symfony/dependency-injection/Tests/Fixtures/CustomDefinition.php:16 Stack trace: #0 {main} thrown in /home/app/htdocs/ninja/vendor/symfony/dependency-injection/Tests/Fixtures/CustomDefinition.php on line 16