在我的情况下，该问题最终通过删除一些约束(实际上是有效的，并且做了应有的约束)得以解决，但是我不认为这是此尴尬错误消息的一般解决方案.

In my case the problem was finally resolved by removing some constraints (that were actually valid and did what they were supposed to), however I don't think that's a general solution to this awkward error message.