When a property in a JPA entity is annotated with a JPA attribute converter or Hibernate's @Type annotation that converts it into a persistable type (e.g. string), the metamodel generator doesn't create an entry for it in the metamodel class. Then when the application starts up, a warning is given: "HHH015011: Unable to locate static metamodel field".
The metamodel generator should consider attribute converters and @Type annotations when it runs.
Java 1.8, JPA 2.2