Fatal error: Uncaught Error: Class 'ProjectExtension' not found in /home/app/htdocs/lidia/vendor/symfony/dependency-injection/Tests/Fixtures/includes/ProjectWithXsdExtension.php:3 Stack trace: #0 {main} thrown in /home/app/htdocs/lidia/vendor/symfony/dependency-injection/Tests/Fixtures/includes/ProjectWithXsdExtension.php on line 3