我已经安装了 symfony-cmf，最后我得到了这个错误：
PHP 致命错误：类 Sonata\MediaBundle\Block\MediaBlockService 包含 1 个抽象方法，因此必须声明为抽象方法或在 /home/jeremy/web/vendor/sonata 中实现其余方法 (Sonata\BlockBundle\Block\BlockServiceInterface::validateBlock) -project/media-bundle/Block/MediaBlockService.php 在第 213 行。
我的 composer.json ：
"php": ">=5.3.3",
"symfony/symfony": "~2.4",
"doctrine/orm": "v2.4.2",
"doctrine/doctrine-bundle": "~1.2",
"twig/extensions": "~1.0",
"symfony/assetic-bundle": "~2.3",
"symfony/swiftmailer-bundle": "~2.3",
"symfony/monolog-bundle": "~2.4",
"sensio/distribution-bundle": "~2.3",
"sensio/framework-extra-bundle": "~3.0",
"sensio/generator-bundle": "~2.3",
"incenteev/composer-parameter-handler": "~2.0",
"friendsofsymfony/user-bundle": "dev-master",
"friendsofsymfony/jsrouting-bundle": "2.0.*@dev",
"jms/security-extra-bundle": "dev-master",
"friendsofsymfony/oauth-server-bundle": "dev-master",
"doctrine/doctrine-fixtures-bundle": "dev-master",
"doctrine/data-fixtures": "@dev",
"jms/serializer-bundle": "0.12.*@dev",
"knplabs/gaufrette": "0.2.*@dev",
"knplabs/knp-gaufrette-bundle": "dev-master",
"vlabs/media-bundle": "v1.1.1",
"lexik/paybox-bundle": "dev-master",
"stof/doctrine-extensions-bundle": "1.1.*@dev",
"sonata-project/admin-bundle": "2.3.*@dev",
"sonata-project/doctrine-orm-admin-bundle": "2.3.*@dev",
"simplethings/entity-audit-bundle": "0.*@dev",
"hwi/oauth-bundle": "0.4.*@dev",
"sonata-project/media-bundle": "2.3.*@dev",
"tilleuls/ckeditor-sonata-media-bundle": "dev-master",
"egeloen/ckeditor-bundle": "2.*",
"sonata-project/formatter-bundle": "2.3.*@dev",
"kunstmaan/voting-bundle": "2.3.*@dev",
"fyneworks/jquery-star-rating": "dev-master",
"friendsofsymfony/comment-bundle": "2.0.*@dev",
"kartik-v/bootstrap-star-rating": "2.5.0",
"symfony-cmf/create-bundle": "1.1.*",
"jackalope/jackalope-doctrine-dbal": "1.1.*",
"doctrine/doctrine-cache-bundle": "1.0.*",
"symfony-cmf/symfony-cmf": "1.1.*",
"symfony-cmf/simple-cms-bundle": "1.1.*",
"nelmio/alice": "1.*"
请问你有什么想法吗，谢谢。