I had a similar issue. In my case the service would work fine on the developer machine but fail when on a QA machine. It turned out that on the QA machine the application wasn't being run as an administrator and didn't have permission to register the endpoint:
HTTP could not register URL http://+:12345/Foo.svc/]. Your process does not have access rights to this namespace (see http://go.microsoft.com/fwlink/?LinkId=70353 for details).
Refer here for how to get it working without being an admin user: https://stackoverflow.com/a/885765/38258