When you right click the svc file and choose View in Browser you might run into an error.
The server was unable to process the request due to an internal error. For more information about the error, either turn on IncludeExceptionDetailInFaults (either from ServiceBehaviorAttribute or from the <serviceDebug> configuration behavior) on the server in order to send the exception information back to the client, or turn on tracing as per the Microsoft .NET Framework 3.0 SDK documentation and inspect the server trace logs.
You will not know what is going on by looking at this error message. When you open Web.config the you will see
change it to
Right click on the svc and choose View in Browser again. You will know the actual problem is cause by
Type ‘WebSiteWCFError.hrom+OMSalaryRow’ cannot be serialized.