Error creating an instance of a proxy class - web-services

Question

This is the error:
The type initializer for 'System.ServiceModel.Diagnostics.TraceUtility' threw an exception.
This error ocurs when I try to instance my proxy class
namespace TesteWebService
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void btnPdv_Click(object sender, EventArgs e)
{
SuporteTecnicoClientProxy proxy = new SuporteTecnicoClientProxy();=> **Here error**
try
{
TPDV pdv = proxy.getCnpjParceiro(txtCnpj.Text);
lblRazao.Text = pdv.RazaoSocial;
lblEndereco.Text = pdv.Endereco;
}
catch (Exception ex)
{ }
finally
{ }
}
}
}
My proxy class
namespace TesteWebService
{
class SuporteTecnicoClientProxy : ClientBase<ISuporteTecnicoContract>, ISuporteTecnicoContract
{
public TPDV getCnpjParceiro(string _cnpj)
{
return this.Channel.getCnpjParceiro(_cnpj);
}
}
}
My Interface
[ServiceContract]
public interface ISuporteTecnicoContract
{
[OperationContract]
[WebGet(UriTemplate = "/{_cnpj}")]
TPDV getCnpjParceiro(string _cnpj);
}
My App.Config
<client>
<endpoint adress="http://localhost:4600/SuporteTecnicoService.svc" binding="webHttpBinding" contract="V99SuporteTecnicoContracts.ISuporteTecnicoContract"
behaviorConfiguration="WebBehavior">
</endpoint>
</client>
<behaviors>
<endpointBehaviors>
<behavior name="WebBehavior">
<webHttp />
</behavior>
</endpointBehaviors>
</behaviors>
What is really going to generate the exception mentioned above. My Interface is other projet. A Class Library Project. So, I have 2 projects. A WCF project(Web Service) and my contract project(POCO class and Interface). This last project Class Library.