private async Task <object> CommandImportExecute(object obj) { DeckImporter deckImporter = obj as DeckImporter; await deckImporter.ImportFromFile(); deck.SelectedVersion.Cards = new PropertiesObservableCollection <CardInstance>(deckImporter.Cards); //curr version shour equal deck.selected version, attch change to reflect clink for remove in deck history CurrentVersion.Cards.CollectionChanged += (s, e) => { RaisePropertyChangedEvent(nameof(ChangesFromCurrentVersion)); }; RaisePropertyChangedEvent(String.Empty); return(null); }