The first time you debug a web service after creating it, Visual Studio will launch the WCF Test Client - a very useful piece of kit - and preload it with the details of your service.In this article, we'll look first at testing your WCF service, and then an all-too-familiar issue that might crop up and spoil your fun!The WCF Test Client looks a bit like SoapUI , and is pretty similar in purpose: It allows you to connect to a service, enter some parameters and submit them to any given service method to see what you get.After the first time you run the WCF Client, Visual Studio will forget all about launching it again until you make significant changes to it - which means when you subsequently hit f5 or choose Debug, it won't run again. It's worth knowing how to bring it up...You can find it again by launching the Visual Studio Command Prompt, and launching wcftestclient.exe from there.Once connected, making use of it is as simple as filling in …