Core Data inheritance and relationship

I have a following data model:

Entity User, which inherits from entity Contact.

Contact has one-to-one relationship with an entity ContactInfo.

User has one-to-many relationship to Contact.

ContactInfo has a reverse relationship to Contact and Contact in its turn has a reverse relationship to User.

I'm creating a ContactInfo object for User:

        ContactInfo *moInfo = [self createContactInfoManagedObject];
        moInfo.contact = userMO;
        userMO.contactInfo = moInfo;

where createContactInfoManagedObject returns an object of type ContactInfo. I'm getting following exception on the line

        moInfo.contact = userMO;


Unacceptable type of value for to-one relationship: property = "contact"; desired type = Contact; given type = NSManagedObject; value = <NSManagedObject: 0x3b2850> (entity: User; id: 0x3d4fa0 <x-coredata://4889CBE0-094B-49DB-B525-C87F7CD1AA68/User/p1> ; data: {
    contacts =     (
     开发者_开发知识库   "0x3d4fa0 <x-coredata://4889CBE0-094B-49DB-B525-C87F7CD1AA68/User/p1>"
    );
    user = "0x3d4fa0 <x-coredata://4889CBE0-094B-49DB-B525-C87F7CD1AA68/User/p1>";
    contactInfo = "0x3ebdc0 <x-coredata:///VCard/t128311BC-4B82-45CF-B87C-9AD38CBC89163>";
}).

My question is what's wrong here? I think something 's wrong with inheritance when I try to assign User entity to a contact relationship. Please advise! Thank you

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Where is your userMO object coming from?

The error message suggests it is an instance of NSManagedObject, but it is expecting an instance of Contact.

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try to cast the object:

 ContactInfo *moInfo =(ContactInfo*) [self createContactInfoManagedObject];