public async void ExecuteAddSubscriptionCommand(object parameter) { Busy = true; BusyContent = "Adding subscription"; try { var subscription = new VisSubscriptionObject { EndpointURL = new Uri(Url), IdentityId = SelectedAcl.IdentityId, IdentityName = SelectedAcl.IdentityName }; await Task.Factory.StartNew(() => { var visService = new VisService(); visService.AddSubscription(Id, new List <VisSubscriptionObject> { subscription }); }); SubscriptionList.Add(subscription); } catch (Exception ex) { MessageBox.Show(ex.ToString()); } finally { Busy = false; } }