diff --git a/OpenUtau.Core/Classic/PluginRunner.cs b/OpenUtau.Core/Classic/PluginRunner.cs
index ab99288ac..0ee65635f 100644
--- a/OpenUtau.Core/Classic/PluginRunner.cs
+++ b/OpenUtau.Core/Classic/PluginRunner.cs
@@ -3,6 +3,7 @@
 using System.IO;
 using System.Linq;
 using System.Security.Cryptography;
+using System.Threading.Tasks;
 using OpenUtau.Core;
 using OpenUtau.Core.Ustx;
 using Serilog;
@@ -44,7 +45,7 @@ public PluginRunner(PathManager pathManager, Action<ReplaceNoteEventArgs> onRepl
             OnError = onError;
         }
 
-        public void Execute(UProject project, UVoicePart part, UNote? first, UNote? last, IPlugin plugin) {
+        public async Task Execute(UProject project, UVoicePart part, UNote? first, UNote? last, IPlugin plugin) {
             if (first == null || last == null) {
                 return;
             }
@@ -59,7 +60,11 @@ public void Execute(UProject project, UVoicePart part, UNote? first, UNote? last
                     return;
                 }
                 Log.Information("Legacy plugin temp file has changed.");
-                var (toRemove, toAdd) = Ust.ParsePlugin(project, part, first, last, sequence, tempFile, encoding: plugin.Encoding);
+                
+                var (toRemove, toAdd) = await Task.Run(() => 
+                    Ust.ParsePlugin(project, part, first, last, sequence, tempFile, encoding: plugin.Encoding)
+                );
+                
                 OnReplaceNote(new ReplaceNoteEventArgs(part, toRemove, toAdd));
             } catch (Exception e) {
                 OnError(new PluginErrorEventArgs("Failed to execute plugin", e));
diff --git a/OpenUtau/ViewModels/PianoRollViewModel.cs b/OpenUtau/ViewModels/PianoRollViewModel.cs
index 2bcec2b0b..751043e22 100644
--- a/OpenUtau/ViewModels/PianoRollViewModel.cs
+++ b/OpenUtau/ViewModels/PianoRollViewModel.cs
@@ -147,27 +147,26 @@ public PianoRollViewModel() {
                 DocManager.Inst.EndUndoGroup();
             });
 
-            legacyPluginCommand = ReactiveCommand.CreateFromTask<Classic.Plugin>(async plugin => {
+            legacyPluginCommand = ReactiveCommand.Create<Classic.Plugin>(async plugin => {
                 if (NotesViewModel.Part == null || NotesViewModel.Part.notes.Count == 0) {
                     return;
                 }
                 DocManager.Inst.ExecuteCmd(new LoadingNotification(typeof(PianoRollWindow), true, "legacy plugin"));
                 
                 try {
-                    await Task.Run(() => {
-                        var part = NotesViewModel.Part;
-                        UNote? first;
-                        UNote? last;
-                        if (NotesViewModel.Selection.IsEmpty) {
-                            first = part.notes.First();
-                            last = part.notes.Last();
-                        } else {
-                            first = NotesViewModel.Selection.FirstOrDefault();
-                            last = NotesViewModel.Selection.LastOrDefault();
-                        }
-                        var runner = PluginRunner.from(PathManager.Inst, DocManager.Inst);
-                        runner.Execute(NotesViewModel.Project, part, first, last, plugin);
-                    });
+                    var part = NotesViewModel.Part;
+                    UNote? first;
+                    UNote? last;
+                    if (NotesViewModel.Selection.IsEmpty) {
+                        first = part.notes.First();
+                        last = part.notes.Last();
+                    } else {
+                        first = NotesViewModel.Selection.FirstOrDefault();
+                        last = NotesViewModel.Selection.LastOrDefault();
+                    }
+                    var runner = PluginRunner.from(PathManager.Inst, DocManager.Inst);
+                    await runner.Execute(NotesViewModel.Project, part, first, last, plugin);
+
                 } catch (Exception e) {
                     DocManager.Inst.ExecuteCmd(new ErrorMessageNotification(e));
                 } finally {
diff --git a/OpenUtau/Views/MainWindow.axaml.cs b/OpenUtau/Views/MainWindow.axaml.cs
index 673b6c6ea..159800d74 100644
--- a/OpenUtau/Views/MainWindow.axaml.cs
+++ b/OpenUtau/Views/MainWindow.axaml.cs
@@ -59,6 +59,7 @@ public MainWindow() {
                 AskIfSaveAndContinue = AskIfSaveAndContinue
             };
 
+            viewModel.NewProject();
             viewModel.AddTempoChangeCmd = ReactiveCommand.Create<int>(tick => AddTempoChange(tick));
             viewModel.DelTempoChangeCmd = ReactiveCommand.Create<int>(tick => DelTempoChange(tick));
             viewModel.AddTimeSigChangeCmd = ReactiveCommand.Create<int>(bar => AddTimeSigChange(bar));
@@ -509,8 +510,8 @@ void OnMenuExpressionss(object sender, RoutedEventArgs args) {
             }
         }
 
-        void OnMenuSingers(object sender, RoutedEventArgs args) {
-            OpenSingersWindow();
+        async void OnMenuSingers(object sender, RoutedEventArgs args) {
+            await OpenSingersWindowAsync();
         }
 
         /// <summary>
@@ -525,11 +526,7 @@ void OnMenuSingers(object sender, RoutedEventArgs args) {
             return null;
         }
 
-        public void OpenSingersWindow() {
-            LoadingWindow.RunAsyncOnUIThread(OpenSingersWindowAsync);
-        }
-
-        public async void OpenSingersWindowAsync() {
+        public async Task OpenSingersWindowAsync() {
             var lifetime = Application.Current?.ApplicationLifetime as IClassicDesktopStyleApplicationLifetime;
             if (lifetime == null) {
                 return;
diff --git a/OpenUtau/Views/PianoRollWindow.axaml.cs b/OpenUtau/Views/PianoRollWindow.axaml.cs
index 42b26a962..c3162c706 100644
--- a/OpenUtau/Views/PianoRollWindow.axaml.cs
+++ b/OpenUtau/Views/PianoRollWindow.axaml.cs
@@ -275,8 +275,10 @@ void OnMenuPlaybackAutoScroll(object sender, RoutedEventArgs args) {
             }
         }
 
-        void OnMenuSingers(object sender, RoutedEventArgs args) {
-            MainWindow?.OpenSingersWindow();
+        async void OnMenuSingers(object sender, RoutedEventArgs args) {
+            if (MainWindow != null) {
+                await MainWindow.OpenSingersWindowAsync();
+            }
             this.Activate();
             try {
                 USinger? singer = null;
@@ -979,7 +981,7 @@ public void PhonemeCanvasDoubleTapped(object sender, TappedEventArgs args) {
             LyricBox?.Show(ViewModel.NotesViewModel.Part, new LyricBoxPhoneme(phoneme!), phoneme!.phoneme);
         }
 
-        public void PhonemeCanvasPointerPressed(object sender, PointerPressedEventArgs args) {
+        public async void PhonemeCanvasPointerPressed(object sender, PointerPressedEventArgs args) {
             LyricBox?.EndEdit();
             if (ViewModel?.NotesViewModel?.Part == null) {
                 return;
@@ -997,7 +999,9 @@ public void PhonemeCanvasPointerPressed(object sender, PointerPressedEventArgs a
                         if (Preferences.Default.OtoEditor == 1 && !string.IsNullOrEmpty(Preferences.Default.VLabelerPath)) {
                             Integrations.VLabelerClient.Inst.GotoOto(singer, hitAliasInfo.phoneme.oto);
                         } else {
-                            MainWindow?.OpenSingersWindow();
+                            if (MainWindow != null) {
+                                await MainWindow.OpenSingersWindowAsync();
+                            }
                             this.Activate();
                             DocManager.Inst.ExecuteCmd(new GotoOtoNotification(singer, hitAliasInfo.phoneme.oto));
                         }
@@ -1795,7 +1799,7 @@ public void AttachExpressions() {
         public void OnNext(UCommand cmd, bool isUndo) {
             if (cmd is LoadingNotification loadingNotif && loadingNotif.window == typeof(PianoRollWindow)) {
                 if (loadingNotif.startLoading) {
-                    LoadingWindow.BeginLoading(this);
+                    LoadingWindow.BeginLoadingImmediate(this);
                 } else {
                     LoadingWindow.EndLoading();
                 }