Fatal error: Uncaught Error: Call to a member function loadFromExtension() on null in /home/cthadmin/public_html/vendor/symfony/framework-bundle/Tests/DependencyInjection/Fixtures/php/serializer_mapping.php:3 Stack trace: #0 {main} thrown in /home/cthadmin/public_html/vendor/symfony/framework-bundle/Tests/DependencyInjection/Fixtures/php/serializer_mapping.php on line 3