UMLR — A PrimitiveType can/cannot have owned attributes.

A datatype can have ownedAttributes. A primitivetype is a subclass of Datatype, so it can have owned attributes. However a primitive type cannot have any substructure. Unfortunately “substructure” is not defined.

This is repeated by the by the classifier definition for PrimitiveType[Class] however there is no OCL that enforces any restriction.

Either eliminate the restriction or define substructure and write some OCL.