I'm using Windows 10 and Visual Studio 2015 with the Blank App (Universal Windows) project. I have tried this in an empty app so the problem is reproducible.
public sealed partial class App : MvvmAppBase
protected override IList<SettingsCommand> GetSettingsCommands()
The compiler says:
error CS0508: 'App.GetSettingsCommands()': return type must be 'IList<SettingsCommand>' to match overridden member 'MvvmAppBase.GetSettingsCommands()'
error CS0731: The type forwarder for type 'Windows.UI.ApplicationSettings.SettingsCommand' in assembly 'Windows' causes a cycle