diff --git a/Azaion.Annotator/Controls/AnnotationControl.cs b/Azaion.Annotator/Controls/AnnotationControl.cs
index 9c22da8..118e305 100644
--- a/Azaion.Annotator/Controls/AnnotationControl.cs
+++ b/Azaion.Annotator/Controls/AnnotationControl.cs
@@ -14,8 +14,8 @@ public class AnnotationControl : Border
 
     private readonly Grid _grid;
     private readonly TextBlock _classNameLabel;
-    
-    private AnnotationClass _annotationClass;
+
+    private AnnotationClass _annotationClass = null!;
     public AnnotationClass AnnotationClass
     {
         get => _annotationClass;
diff --git a/Azaion.Annotator/Controls/CanvasEditor.cs b/Azaion.Annotator/Controls/CanvasEditor.cs
index c21dee3..4ab9184 100644
--- a/Azaion.Annotator/Controls/CanvasEditor.cs
+++ b/Azaion.Annotator/Controls/CanvasEditor.cs
@@ -22,15 +22,15 @@ public class CanvasEditor : Canvas
     private readonly Line _verticalLine;
     private readonly TextBlock _classNameHint;
     
-    private Rectangle _curRec;
-    private AnnotationControl _curAnn;
+    private Rectangle _curRec = new();
+    private AnnotationControl _curAnn = null!;
     
     private const int MIN_SIZE = 20;
-    
-    public FormState FormState { get; set; }
-    public IMediator Mediator { get; set; }
 
-    private AnnotationClass _currentAnnClass; 
+    public FormState FormState { get; set; } = null!;
+    public IMediator Mediator { get; set; } = null!;
+
+    private AnnotationClass _currentAnnClass = null!;
     public AnnotationClass CurrentAnnClass
     {
         get => _currentAnnClass; 
diff --git a/Azaion.Annotator/Controls/UpdatableProgressBar.cs b/Azaion.Annotator/Controls/UpdatableProgressBar.cs
index d017842..8171c3f 100644
--- a/Azaion.Annotator/Controls/UpdatableProgressBar.cs
+++ b/Azaion.Annotator/Controls/UpdatableProgressBar.cs
@@ -7,7 +7,7 @@ namespace Azaion.Annotator.Controls
     {
         public delegate void ValueChange(double oldValue, double newValue);
 
-        public event ValueChange? ValueChanged;
+        public new event ValueChange? ValueChanged;
 
         public UpdatableProgressBar() : base()
         {
diff --git a/Azaion.Annotator/MainWindow.xaml.cs b/Azaion.Annotator/MainWindow.xaml.cs
index 779f0aa..33a6be7 100644
--- a/Azaion.Annotator/MainWindow.xaml.cs
+++ b/Azaion.Annotator/MainWindow.xaml.cs
@@ -24,13 +24,11 @@ public partial class MainWindow
     private readonly HelpWindow _helpWindow;
     private readonly TimeSpan _annotationTime = TimeSpan.FromSeconds(1);
     
-    public ObservableCollection<AnnotationClass> AnnotationClasses { get; set; }
+    public ObservableCollection<AnnotationClass> AnnotationClasses { get; set; } = new();
     private bool _suspendLayout;
 
     public Dictionary<string, List<AnnotationInfo>> Annotations { get; set; } = new();
-    
-    public bool ShowHelpOnStart { get; set; }
-    
+        
     public MainWindow(LibVLC libVLC, MediaPlayer mediaPlayer,
         IMediator mediator,
         FormState formState,
@@ -72,8 +70,7 @@ public partial class MainWindow
         if (LvFiles.Items.IsEmpty) 
             BlinkHelp(HelpTexts.HelpTextsDict[HelpTextEnum.Initial]);
         
-        ShowHelpOnStart = _config.ShowHelpOnStart;
-        if (ShowHelpOnStart) 
+        if (_config.ShowHelpOnStart) 
             _helpWindow.Show();
     }
 
@@ -131,15 +128,17 @@ public partial class MainWindow
             }).ToList();
             
             //remove annotations: either in 1 sec, either earlier if there is next annotation in a dictionary 
-            var strs = curTime.Split("_");
-            var timeStr = strs.LastOrDefault();
-            var ts = TimeSpan.FromMilliseconds(int.Parse(timeStr)*100);
-            var timeSpanRemove = Enumerable.Range(1, ((int)_annotationTime.TotalMilliseconds / 100) - 1)
+            var timeStr = curTime.Split("_").LastOrDefault();
+            if (!int.TryParse(timeStr, out var time))
+                return;
+            
+            var ts = TimeSpan.FromMilliseconds(time * 100);
+            var timeSpanRemove = Enumerable.Range(1, (int)_annotationTime.TotalMilliseconds / 100 - 1)
                 .Select(x =>
                 {
-                    var time = TimeSpan.FromMilliseconds(x * 100);
-                    var fName = _formState.GetTimeName(ts.Add(time));
-                    return Annotations.ContainsKey(fName) ? time : (TimeSpan?)null;
+                    var timeNext = TimeSpan.FromMilliseconds(x * 100);
+                    var fName = _formState.GetTimeName(ts.Add(timeNext));
+                    return Annotations.ContainsKey(fName) ? timeNext : (TimeSpan?)null;
                 }).FirstOrDefault(x => x != null) ?? _annotationTime;
             
             _ = Task.Run(async () =>
@@ -240,8 +239,10 @@ public partial class MainWindow
         };
         if (dlg.ShowDialog() != CommonFileDialogResult.Ok)
             return;
+
+        if (!string.IsNullOrEmpty(dlg.FileName)) 
+            _config.VideosDirectory = dlg.FileName;
         
-        _config.VideosDirectory = dlg.FileName;
         ReloadFiles();
     }
 
diff --git a/Azaion.Annotator/PlayerControlHandler.cs b/Azaion.Annotator/PlayerControlHandler.cs
index 3b89fc6..efbd000 100644
--- a/Azaion.Annotator/PlayerControlHandler.cs
+++ b/Azaion.Annotator/PlayerControlHandler.cs
@@ -25,9 +25,13 @@ public class PlayerControlHandler(LibVLC libVLC, MediaPlayer mediaPlayer, MainWi
         { Key.Delete, PlaybackControlEnum.RemoveSelectedAnns },
         { Key.X, PlaybackControlEnum.RemoveAllAnns }
     };
-    
-    public async Task Handle(AnnClassSelectedEvent notification, CancellationToken cancellationToken) => 
+
+    public async Task Handle(AnnClassSelectedEvent notification, CancellationToken cancellationToken)
+    {
         SelectClass(notification.AnnotationClass);
+        await Task.CompletedTask;
+    } 
+        
 
     private void SelectClass(AnnotationClass annClass)
     {