请求因空响应而失败。当呼叫第三方服务器时

Question

当我尝试连接到服务器时，我正在尝试将cognos BI服务器与控制台应用程序集成我的错误状态为“请求因空响应而失败”。

credentialXML.AppendFormat("<namespace>{0}</namespace>", "");
credentialXML.AppendFormat("<username>{0}</username>", "username");
credentialXML.AppendFormat("<password>{0}</password>", "Password");
credentialXML.Append("</credential>");

//The csharp toolkit encodes the credentials
string encodedCredentials = credentialXML.ToString();
xmlEncodedXML xmlEncodedCredentials = new xmlEncodedXML();
xmlEncodedCredentials.Value = encodedCredentials;
searchPathSingleObject[] emptyRoleSearchPathList = new searchPathSingleObject[0];
cBICMS.logon(xmlEncodedCredentials, null);