尝试加载类“ ManyToManyObjectRelation”错误Pimcore 5.5.4

Question

在Fresh PIM安装中，出现以下错误：

在definition_blogArticle.php第221行中：

Attempted to load class "ManyToManyObjectRelation" from namespace "Pimcore\Model\DataObject\ClassDefinition\Data".

Did you forget a "use" statement for another namespace?

我使用了“基本演示包（PHP模板）”。

请帮助。