IllegalArgumentException - expecting IdClass mapping in Hibernate

Issue

• server.log entry similar to

MSC000001: Failed to start service jboss.persistenceunit."<service>.war#translatorPersistenceUnit": org.jboss.msc.service.StartException in service jboss.persistenceunit."<service>.war#translatorPersistenceUnit": java.lang.IllegalArgumentException: expecting IdClass mapping
    at org.jboss.as.jpa.service.PersistenceUnitServiceImpl$1$1.run(PersistenceUnitServiceImpl.java:172)
    at org.jboss.as.jpa.service.PersistenceUnitServiceImpl$1$1.run(PersistenceUnitServiceImpl.java:117)
    at org.wildfly.security.manager.WildFlySecurityManager.doChecked(WildFlySecurityManager.java:667)
    at org.jboss.as.jpa.service.PersistenceUnitServiceImpl$1.run(PersistenceUnitServiceImpl.java:182)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
    at org.jboss.threads.JBossThread.run(JBossThread.java:320)
Caused by: java.lang.IllegalArgumentException: expecting IdClass mapping
    at org.hibernate.jpa.internal.metamodel.AttributeFactory$3.resolveMember(AttributeFactory.java:966)
    at org.hibernate.jpa.internal.metamodel.AttributeFactory$5.resolveMember(AttributeFactory.java:1024)
    at org.hibernate.jpa.internal.metamodel.AttributeFactory.determineAttributeMetadata(AttributeFactory.java:449)
    at org.hibernate.jpa.internal.metamodel.AttributeFactory.buildIdAttribute(AttributeFactory.java:128)
    at org.hibernate.jpa.internal.metamodel.MetadataContext.buildIdClassAttributes(MetadataContext.java:343)
    at org.hibernate.jpa.internal.metamodel.MetadataContext.applyIdMetadata(MetadataContext.java:275)
    at org.hibernate.jpa.internal.metamodel.MetadataContext.wrapUp(MetadataContext.java:196)
    at org.hibernate.jpa.internal.metamodel.MetamodelImpl.buildMetamodel(MetamodelImpl.java:82)
    at org.hibernate.jpa.internal.EntityManagerFactoryImpl.<init>(EntityManagerFactoryImpl.java:113)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:890)
    at org.jboss.as.jpa.hibernate5.TwoPhaseBootstrapImpl.build(TwoPhaseBootstrapImpl.java:44)
    at org.jboss.as.jpa.service.PersistenceUnitServiceImpl$1$1.run(PersistenceUnitServiceImpl.java:154)
    ... 7 more