Must a Receive Activity have a corresponding SendReply Activity?

I leared here that in order to declare FaultContracts you had to have a SendReply activity in your workflow that returns object of type FaultException.

I have declared Receive and SendReply activities in my workflow. I only want to send a reply if something goes wrong, so I created a SendReply activity that returns object of type FaultException. But, when things don't go wrong, I get a timeout exception on t开发者_运维问答he client.

Do I have to send a reply back? There's no real useful data for me to send back.

Yes, a service with an empty response is not the same as a service with no response (a One-Way service). One way services themselves have no answer (and usually can't serve meaningful faults either), but that does not seem to be your case, so you'd still need a SendReply activity with the empty response, as the client expects it.