EDIT: I moved this from the Silverlight forum hoping that someone here might be able to shed some light. This is a GP issue not Silverlight.
I stood up a GP service yesterday using the Clip and Ship example from ESRI, found here: ArcGIS Help (10.2, 10.2.1, and 10.2.2) . Using the Silverlight example for extracting data found here: ArcGIS API for Silverlight - Interactive Samples (without modifications), I am successfully able to extract data to a shape file or fgdb. However, if I try to extract to a dwg I am given the message that it was successful and when I download the zip file it is empty, no dwg is produced. If I go to the scratch space on the server to look at the output directory for that job its output content is empty as well. This led me to believe that something is wrong with the GP. To test it, I opened ArcMap, ran the GP and it produced a dwg without any issue. I am not to sure what else to try. I am running ArcGIS for Server 10.2 and version 3.1 for the Silverlight api. Any help is greatly appreciated!