Adding reference error

[JeffersonLegaspi]

Help. I just wanted to add FeatureData form on my windows phone 8.1 app. and i added Esri runtime toolkit via Nuget . After running i got this error. How can i fix this?

Here's screenshot of my Reference folder

[DominiqueBroux]

By adding the ArcGIS toolkit via Nuget you also automatically add the runtime from Nuget (the toolkit depends on this package). So you end up with 2 versions of the ArcGIS runtime one from the SDK, one from Nuget.

It's not possible to mix SDK and Nuget.

To clean up your project I suggest you remove all ArcGIS Runtime references from your project and then add the 2 ArcGIS Runtime Nuget packages.

[JeffersonLegaspi]

Thank you dom