Erro ao acessar metodo no ejb

[Russo]

Boa tarde,

Alguem conhece esse erro?

javax.ejb.EJBException
	at com.sun.ejb.containers.EJBContainerTransactionManager.processSystemException(EJBContainerTransactionManager.java:748)
	at com.sun.ejb.containers.EJBContainerTransactionManager.completeNewTx(EJBContainerTransactionManager.java:698)
	at com.sun.ejb.containers.EJBContainerTransactionManager.postInvokeTx(EJBContainerTransactionManager.java:503)
	at com.sun.ejb.containers.BaseContainer.postInvokeTx(BaseContainer.java:4475)
	at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:2009)
	at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:1979)
	at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:220)
	at com.sun.ejb.containers.EJBLocalObjectInvocationHandlerDelegate.invoke(EJBLocalObjectInvocationHandlerDelegate.java:88)
	at $Proxy283.listAll(Unknown Source)
	at br.com.bi.dao.__EJB31_Generated__DimRegiaoDao__Intf____Bean__.listAll(Unknown Source)
	at RegiaoBean.lista(RegiaoBean.java:27)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

>>>>>> managed bean

@Named("regiaoBean")
@SessionScoped
public class RegiaoBean implements Serializable {

    private DimRegiao regiaoSelecionada;
    
    @EJB(name="DimRegiaoDao")
    private DimRegiaoDao dao;

    public RegiaoBean() {
        //this.dao = new DimRegiaoDao();
    }

    public List<DimRegiao> lista() {
        return this.dao.listAll();
    }
}

>>>> 

@Stateless(name="DimRegiaoDao")
public class DimRegiaoDao implements java.io.Serializable{
    
    @PersistenceContext(unitName = "BIPU")
    private EntityManager em;

    public DimRegiaoDao() {
    }

    public List<DimRegiao> listAll() {
        //Query query = em.createNamedQuery("DimRegiao.findAll");
        Query query = em.createQuery("SELECT d FROM DimRegiao d", DimRegiao.class);
        return query.getResultList();
    }
    
    
}