Hack that fixes issue #719 - thx XuTpuK :)

src/Program.cs

@@ -1,4 +1,6 @@
 using System;
+using System.Diagnostics;
+using System.Threading;
 using System.Windows.Forms;
 using Nikse.SubtitleEdit.Forms;
 
@@ -12,9 +14,68 @@ namespace Nikse.SubtitleEdit
         [STAThread]
         private static void Main()
         {
+            // Add the event handler for handling UI thread exceptions to the event.
+            Application.ThreadException += Application_ThreadException;
+
+            // Set the unhandled exception mode to force all Windows Forms errors to go through our handler.
+            Application.SetUnhandledExceptionMode(UnhandledExceptionMode.CatchException);
+
+            // Add the event handler for handling non-UI thread exceptions to the event. 
+            AppDomain.CurrentDomain.UnhandledException += CurrentDomain_UnhandledException;
+
             Application.EnableVisualStyles();
             Application.SetCompatibleTextRenderingDefault(false);
             Application.Run(new Main());
         }
+
+        static void Application_ThreadException(object sender, ThreadExceptionEventArgs e)
+        {
+            if (!(e.Exception is System.Globalization.CultureNotFoundException)) // To avoid error when changing language (on some computers) - see https://github.com/SubtitleEdit/subtitleedit/issues/719
+            {
+                ShowThreadExceptionDialog("Unhandled exception in SubtitleEdit.exe", e.Exception);
+            }
+        }
+
+      
+        // Handle the UI exceptions by showing a dialog box, and asking the user whether 
+        // or not they wish to abort execution. 
+        // NOTE: This exception cannot be kept from terminating the application - it can only  
+        // log the event, and inform the user about it.  
+        private static void CurrentDomain_UnhandledException(object sender, UnhandledExceptionEventArgs e)
+        {
+            try
+            {
+                var ex = (Exception)e.ExceptionObject;
+                const string errorMsg = "An error occurred in Subtitle Edit. Please contact the adminstrator with the following information:\n\n";
+
+                // Since we can't prevent the app from terminating, log this to the event log. 
+                if (!EventLog.SourceExists("ThreadException"))
+                {
+                    EventLog.CreateEventSource("ThreadException", "Application");
+                }
+
+                // Create an EventLog instance and assign its source.
+                var myLog = new EventLog { Source = "ThreadException" };
+                myLog.WriteEntry(errorMsg + ex.Message + "\n\nStack Trace:\n" + ex.StackTrace);
+            }
+            catch (Exception exc)
+            {
+                try
+                {
+                    MessageBox.Show("Fatal Non-UI Error in Subtitle Edit", "Fatal Non-UI Error. Could not write the error to the event log. Reason: " + exc.Message, MessageBoxButtons.OK, MessageBoxIcon.Stop);
+                }
+                finally
+                {
+                    Application.Exit();
+                }
+            }
+        }
+
+        private static void ShowThreadExceptionDialog(string title, Exception e)
+        {
+            var errorMsg = "An application error occurred. Please contact the adminstrator with the following information:\n\n" + e.Message + "\n\nStack Trace:\n" + e.StackTrace;
+            MessageBox.Show(errorMsg, title, MessageBoxButtons.AbortRetryIgnore, MessageBoxIcon.Stop);
+        }
+
     }
 }