Symfony树配置构建器没有能够加载

Question

    $rootNode = $treeBuilder->root('payment_onpay');

    $rootNode
        ->children()
            ->arrayNode('configuration')
                ->children()
                    ->integerNode('client_id')->end()
                    ->scalarNode('client_secret')->end()
                ->end()
            ->end() // twitter
        ->end()
    ;

onpay.yml：

payment_onpay:
  configuration:
    client_id: "id"
    client_secret: "secret"

运行应用程序抛出异常后： 致命错误：未捕获异常'Symfony \ Component \ DependencyInjection \ Exception \ InvalidArgumentException'，带有消息'没有扩展程序可以加载“payment_onpay”的配置（在/var/public_html/game-server.loc/www/src/Payment /OnpayBundle/DependencyInjection/../Resources/config/onpay.yml）。查找命名空间“payment_onpay”，在第356行的/var/public_html/game-server.loc/www/vendor/symfony/symfony/src/Symfony/Component/DependencyInjection/Loader/YamlFileLoader.php中找不到'