I have written web services in .net to integrate .net sites to our CRM server. I want to change my present .net web services to WCF Services. I have done the following: I have downloaded the Users Custom wsdl, Web Services 2.0. With the wsdl and Visual Studio 2010, I used the .net svcutil utility to create a .net WCF Service class. I then tried to get some users using the following code in a console app: UserClient usr = new UserClient(); UserQueryPage_Input objUserQryParam = new UserQueryPage_Input(); UserQueryPage_Output objUserQryOut = new UserQueryPage_Output(); ListOfUserQuery lq = new ListOfUserQuery(); UserQuery uq = new UserQuery(); queryType qt = new queryType(); qt.Value = "'Test'"; lq.pagesize = "100"; lq.startrownum = "1"; uq.LastName = qt; lq.User = uq; usr.ClientCredentials.UserName.UserName = ConfigurationManager.AppSettings["CRMUserName"]; usr.ClientCredentials.UserName.Password = ConfigurationManager.AppSettings["CRMPassword"]; objUserQryParam.ListOfUser = lq; //When running this line, I get an exception with a message of "Server" objUserQryOut = usr.UserQueryPage(objUserQryParam); I can not find any errors registered on the CRM in the web service. Can someone tell me if WCF is supported and where I can find failed requests to the CRM web services. Thanks!