NHibernate: NHibernateConfigException

Question

Hi, I'm starting with VB.NET and NHibernate but i'm getting this exception:

NHibernateConfigException was unhandled
An exception occurred during configuration of persistence layer.

This is the code

Dim configuration As New Cfg.Configuration() configuration.Configure() configuration.AddFile("person.hbm.xml")

    Dim factory As ISessionFactory = configuration.BuildSessionFactory
    Dim session As ISession = factory.OpenSession

    Dim transaction As ITransaction = session.BeginTransaction()

    Dim person As New Person
    person.Name = "Willian"
    person.Age = 22

    session.Save(person)
    transaction.Commit()
    session.Close()

How could I solve that? Thanks.