客户端身份验证方案“匿名”对HTTP请求进行了未经授权的访问（通过C＃基本身份验证写入）

尝试连接到webService时出现服务器错误。你知道为什么吗？

错误

{System.Collections.Generic.SynchronizedReadOnlyCollection}

代码

            BasicHttpBinding basicbinding = new BasicHttpBinding();
            basicbinding.Security.Mode = BasicHttpSecurityMode.TransportCredentialOnly;
            basicbinding.Security.Transport.ClientCredentialType = HttpClientCredentialType.Basic;
            basicbinding.Name = "HTTP_Port";

            WSPI.InvoiceCheck_OutClient invoiceCheck_OC = new WSPI.InvoiceCheck_OutClient(basicbinding, new EndpointAddress(new Uri("http://example.example.eu:51200/XISOAPAdapter/MessageServlet?senderParty=&")));
            invoiceCheck_OC.ClientCredentials.UserName.UserName = "Login";
            invoiceCheck_OC.ClientCredentials.UserName.Password = "Password";


            WSPI.InvoiceCheck invoiceCheck = new WSPI.InvoiceCheck();

            WSPI.InvoiceCheck_OutRequest invoiceCheck_OR = new WSPI.InvoiceCheck_OutRequest();

            WSPI.InvoiceConfirm invoiceCheck_IC = new WSPI.InvoiceConfirm();

            invoiceCheck.InvoiceNo = "1000000";
            invoiceCheck.IssueDate = "2014-01-01";
            invoiceCheck.VatNo = "88090302342";
            invoiceCheck.Username = "SuperRafal";


            string response = invoiceCheck_OC.InvoiceCheck_Out(invoiceCheck).Response.ToString();