Logout Problem in Authentication service

Problem with AuthService.Logout() Method with ria services.

Error: Message: “Object reference not set to an instance of an object”
Stack trace:
at System.Web.Ria.DataServiceQueryRequest.GetOrderedQueryParts(HttpRequest request)
at System.Web.Ria.DataServiceQueryRequest.Invoke(DomainService domainService)
at System.Web.Ria.DataService.System.Web.IHttpHandler.ProcessRequest(HttpContext contex

Solution:

This issue is solved by using the latest WCF Ria services