Geoprocessing Package Error

Discussion created by GCosanesriturkey-com-tr-esridist Employee on Nov 24, 2011
Latest reply on Dec 7, 2011 by GCosanesriturkey-com-tr-esridist
I build Geoprocessing Package and I want to use the GPK file as follows:

   LocalGeoprocessingService.GetServiceAsync(@"C:\GpkApp\GpkApp\bin\Debug\SimpleBuffer.gpk", GPServiceType.Execute, (gpService) =>
                if (gpService.Error != null)
                _gpTask = new Geoprocessor(gpService.UrlGeoprocessingService + "/" +
and  _gpTask  value  return null.
What may be missing in the package of geoprocessing? or Where else could mistake?