Hi, NetBeans 11.1.
The code generated by NetBeans for the injection of an EntityManager is not adapted to the CMT (Container Managed Transaction) mode. "Generate" menu for "Insert code..." > "Use Entity Manager...". The generated code: @PersistenceContext(unitName = "xxx") private EntityManager em; @Resource private javax.transaction.UserTransaction utx; public void persist(Object object) { try { utx.begin(); em.persist(object); utx.commit(); } catch (Exception e) { Logger.getLogger(getClass().getName()).log(Level.SEVERE, "exception caught", e); throw new RuntimeException(e); } } It should be @PersistenceContext(unitName = xxx") private EntityManager em; public void persist(Object object) { em.persist(object); } Richard