WCM iparts Null Reference Exception

We're on version 15.2.10. iMIS and WCM with iparts are working fine on the imis application server. However we recently installed WCM (standalone installation) on the web server and have set up a wcm website (copy of the members site) on this server. The site seems to load okay but when we tried to access any iParts we get a null reference exception below. SOA appears to be working fine.

Any suggestions on solving this is appreciated.

 

Service Error:

An error has occurred while consuming this service. Please contact your administrator for more information. Error ID: f7c07bfe-2a10-4914-8517-f683ebef7c26
Timestamp: 3/10/2012 12:41:43 PM
Message Id: f7c07bfe-2a10-4914-8517-f683ebef7c26
An exception of type 'NullReferenceException' occurred
Type: NullReferenceException
Message: Object reference not set to an instance of an object.
Source: System.Web
Stack Trace:    at System.Web.Security.Roles.GetRolesForUser(String username)
  at Asi.Soa.ServiceModelEx.ClaimsAuthorizationPolicy.MapClaims(IIdentity identity)
  at Asi.Soa.ServiceModelEx.ClaimsAuthorizationPolicy.Evaluate(EvaluationContext evaluationContext, Object& state)
  at System.IdentityModel.SecurityUtils.CreateDefaultAuthorizationContext(IList`1 authorizationPolicies)
  at System.IdentityModel.Policy.AuthorizationContext.CreateDefaultAuthorizationContext(IList`1 authorizationPolicies)
  at System.ServiceModel.Dispatcher.SecurityImpersonationBehavior.GetCustomPrincipal(ServiceSecurityContext securityContext)
  at System.ServiceModel.Dispatcher.SecurityImpersonationBehavior.SetCurrentThreadPrincipal(ServiceSecurityContext securityContext, Boolean& isThreadPrincipalSet)
  at System.ServiceModel.Dispatcher.SecurityImpersonationBehavior.StartImpersonation(MessageRpc& rpc, IDisposable& impersonationContext, IPrincipal& originalPrincipal, Boolean& isThreadPrincipalSet)
  at System.ServiceModel.Dispatcher.DispatchOperationRuntime.InvokeBegin(MessageRpc& rpc)
  at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage5(MessageRpc& rpc)
  at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage41(MessageRpc& rpc)
  at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage4(MessageRpc& rpc)
  at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage31(MessageRpc& rpc)
  at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage3(MessageRpc& rpc)
  at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage2(MessageRpc& rpc)
  at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage11(MessageRpc& rpc)
  at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage1(MessageRpc& rpc)
  at System.ServiceModel.Dispatcher.MessageRpc.Process(Boolean isOperationContextSet)