We are getting this for some users when they access their preferences:
Unhandled Service Exception
Exception: ValidationException
Message: '' is not a valid XMPP id
Stack Trace: at Continua.Modules.Core.Services.MembershipService.GetXmppDetails(String xmppId)
at SyncInvokeGetXmppDetails(Object , Object[] , Object[] )
at System.ServiceModel.Dispatcher.SyncMethodInvoker.Invoke(Object instance, Object[] inputs, Object[]& outputs)
at System.ServiceModel.Dispatcher.DispatchOperationRuntime.InvokeBegin(MessageRpc& rpc)
at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage5(MessageRpc& rpc)
at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage31(MessageRpc& rpc)
at System.ServiceModel.Dispatcher.MessageRpc.Process(Boolean isOperationContextSet)
It seems that this only happens if they do not have provided any XMPP ID yet.