Deploy ear to GlassFish

Good day, everybody!
I have one question.
I try to deploy ear application using persistent.xml.
But when I deploy I receive answer:
Error occurred during deployment: Exception while preparing the app : [PersistenceUnit: NewPersistenceUnit] Unable to build Hibernate SessionFactory. Please see server.log for more details. Exception while invoking class org.glassfish.persistence.jpa.JPADeployer prepare method : javax.persistence.PersistenceException: [PersistenceUnit: NewPersistenceUnit] Unable to build Hibernate SessionFactory [PersistenceUnit: NewPersistenceUnit] Unable to build Hibernate SessionFactory Exception while invoking class org.glassfish.persistence.jpa.JPADeployer prepare method : javax.persistence.PersistenceException: [PersistenceUnit: NewPersistenceUnit] Unable to build Hibernate SessionFactory [PersistenceUnit: NewPersistenceUnit] Unable to build Hibernate SessionFactory

What does at mean?