Fatal error: Uncaught TypeError: Invalid return value: callable object expected, "null" returned from "/home/blacksilzu/symfony/my_project_dir/vendor/autoload_runtime.php". in /home/blacksilzu/symfony/my_project_dir/vendor/autoload_runtime.php:12 Stack trace: #0 {main} thrown in /home/blacksilzu/symfony/my_project_dir/vendor/autoload_runtime.php on line 12