I created a Model in ArcMap 10.3.1 for finding routes between two points which takes input Network Dataset and a Feature layer(for giving stops). This I have done following steps in the tutorial Author and publish a geoprocessing model—ArcGIS Runtime SDK for Qt | ArcGIS for Developers . I used network tools like Make Route Layer, Add Locations, Solve. I am able to get result as required when I run in Arc Map. When I used this result to create gpk and use in Arc GIS Runtime, I am getting output
"GET GPServer/na/execute: The specified task was not found"
na is my model name.