Update - Display exceptions

Update - Run installer as admin so it well, works

src/Artemis.UI/Screens/Settings/Dialogs/UpdateDialogViewModel.cs

@@ -1,4 +1,5 @@
-using System.Threading.Tasks;
+using System;
+using System.Threading.Tasks;
 using Artemis.Core;
 using Artemis.UI.Services;
 using Artemis.UI.Shared.Services;
@@ -9,12 +10,16 @@ namespace Artemis.UI.Screens.Settings.Dialogs
     public class UpdateDialogViewModel : DialogViewModelBase
     {
         private readonly JToken _buildInfo;
+        private readonly IDialogService _dialogService;
         private readonly IUpdateService _updateService;
+        private bool _canUpdate = true;
 
-        public UpdateDialogViewModel(JToken buildInfo, IUpdateService updateService)
+        public UpdateDialogViewModel(JToken buildInfo, IUpdateService updateService, IDialogService dialogService)
         {
             _buildInfo = buildInfo;
             _updateService = updateService;
+            _dialogService = dialogService;
+            
             CurrentBuild = Constants.BuildInfo.BuildNumberDisplay;
             LatestBuild = buildInfo?.SelectToken("value[0].buildNumber")?.Value<string>();
         }
@@ -22,9 +27,28 @@ namespace Artemis.UI.Screens.Settings.Dialogs
         public string CurrentBuild { get; }
         public string LatestBuild { get; }
 
+        public bool CanUpdate
+        {
+            get => _canUpdate;
+            set => SetAndNotify(ref _canUpdate, value);
+        }
+
         public async Task Update()
         {
-            await _updateService.ApplyUpdate();
+            try
+            {
+                CanUpdate = false;
+                await _updateService.ApplyUpdate();
+            }
+            catch (Exception e)
+            {
+                _dialogService.ShowExceptionDialog("An exception occurred while applying the update", e);
+            }
+            finally
+            {
+                CanUpdate = true;
+            }
+
             Session.Close();
         }
     }