fix bug

Author: Bishbash777

Torch.Server/Views/LogEventViewer.xaml.cs

@@ -60,7 +60,8 @@ public LogEventViewer()
             DataContext = new LogViewModel();
 
             NlogCustomTarget.LogEventReceived += LogEvent;
-            
+            TorchServer.Instance.SessionUnloading += Unloading;
+
 
             //on loaded event
             Loaded += (sender, args) =>
@@ -71,6 +72,11 @@ public LogEventViewer()
             };
         }
 
+        private void Unloading()
+        {
+            NlogCustomTarget.LogEventReceived -= LogEvent;
+        }
+
         private void LogEvent(LogEventInfo obj)
         {
             // Use Dispatcher.Invoke to ensure that the following code block is executed on the UI thread.
@@ -95,8 +101,6 @@ private void LogEvent(LogEventInfo obj)
                 }
             });
         }
-
-
         private void LevelFilterComboBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
         {
             ApplyFilters();