If you find yourself looking at error responses from the WCF data service that only tell you ‘An error occurred while processing this request’ from a WCF Data Service then…
config.UseVerboseErrors = true;
to the method:
public static void InitializeService(DataServiceConfiguration config)
And you will get the full details of why your data service isn’t doing what you want it to.
If you want you can also override the HandleException method to capture the exception on the server:
protected override void HandleException(HandleExceptionArgs args)
//Do something to handle the exception.
Hope this helps – sure has helped me!