Read original post at Jim Galasyn's Learning Curve
If you have an app in the Windows Store already, and you used the Split App (XAML) template as the basis of your app, you’ll notice that the VS2013 compiler complains when you retarget the project to Windows 8.1 and build it:
Warning: 'Windows.ApplicationModel.DataTransfer.DataPackage.SetUri(System.Uri)' is obsolete: 'SetUri may be altered or unavailable for releases after Windows 8.1. Instead, use SetWebLink or SetApplicationLink.'