Because I get DataSet does not support System.Nullable when setting data in Crystal Report?

I get an error with Nullable when I set the data to my Crystal Report

As a data engine I use a model, it's the same model that receives the data and I set it to my Crystal Report

namespace SistemaControl_API.Models
{
   public class Get_IDDepartamento
    {
        public int IdDepartamento { get; set; }
        public int IdUnidad { get; set; }
        public int IdEmpresa { get; set; }
        public string NombreDepto { get; set; }
        public Nullable<int> IdResponsable { get; set; }
        public string Direccion { get; set; }
        public string Colonia { get; set; }
        public string CodigoPostal { get; set; }
        public Nullable<int> CveMunicipio { get; set; }
        public Nullable<int> CveEstado { get; set; }
        public string Telefono { get; set; }
        public string Telefono2 { get; set; }
        public string Extension { get; set; }
        public string Fax { get; set; }
        public string FuncionPrincipal { get; set; }
        public Nullable<bool> EstatusDepto2 { get; set; }
        public string NUnidad { get; set; }
        public string NombreEmpresa { get; set; }
        public string NombreEdo { get; set; }
        public string NombreMpio { get; set; }
        public string Nombre { get; set; }
        public string Nombre2 { get; set; }
        public string Apellido1 { get; set; }
        public string Apellido2 { get; set; }
    }
}

thus I establish the data:

var GetList = _Departamento_Business.GetIdDepartamento(idDepto, idUnidad, idEmpresa);

var DatosDepto = Mapper.Map<List<Entidad.Get_IDDepartamento_Result>, List<Datos.Get_IDDepartamento>>(GetList);

 ReportDocument rd = new ReportDocument();
 rd.Load(HttpContext.Current.Server.MapPath("~/Views/Reports/CatDeptosCR.rpt"));
rd.SetDataSource(DatosDepto);

are the same data and are even of the string type, which could be happening? The weirdest thing is that they do not have null fields.