I was getting this error when trying to add an icon on tvOS in Xamarrin. The full error message is:
xamarin The image stack "App Icon - Large" must have at least 2 layers with applicable content. Although it has 2 layers, none have applicable content.
My method around this for tvOS layered icons was as follows:
1) Don't add the images via Xamarin, but load the generated Xcode project in Xcode and add from there.
2) After doing this the combination of Xcode and Xamarin then add the images to two places: