Cause
This error occurs if you have defined a constraint on a reference and the constraint is not valid. This can be for one of the following reasons.
The reference is not an explicit inverse reference.
The schema type of the constraint is not compatible with the reference type. The reference type (or its member type for collections) must be the same as or a subclass of the constraint schema type.
The constraint must be a JADE condition method with no parameters.
Action
Correct the constraint so that it conforms to the above rules.