Problems related to samples should be posted where the sample came from. We have no knowledge of whatever this sample you are talking about is. This forum is also for C#-specific questions only so even if we had the code we wouldn't be able to help much.
The error itself indicates the app is trying to connect to what looks like a web app running on your local machine. Most likely you are not running that web app and it fails. Refer to the samples documentation and they probably tell you how to start both
apps (probably in the same solution) so it will work.
Michael Taylor http://www.michaeltaylorp3.net