ViewModel
public class MyViewModel:ReactiveObject, IRoutableViewModel{ private ReactiveList _appExtensions; p
Change
GetApplicationExtensions .ObserveOn(RxApp.MainThreadScheduler) .SubscribeOn(RxApp.TaskpoolScheduler)
to
GetApplicationExtensions .SubscribeOn(RxApp.TaskpoolScheduler) .ObserveOn(RxApp.MainThreadScheduler)
ObserveOn should be after SubscribeOn