vb.net - Exception handling problem in release mode

Question

I have application with this code:

Module Startup
  <STAThread()> _
  Public Sub Main()
    Try
      Application.EnableVisualStyles()
      Application.SetCompatibleTextRenderingDefault(False)

      InitApp()

      Dim login As New LoginForm()
      Dim main As New MainForm()

      Application.Run(login)

      If login.DialogResult = DialogResult.OK Then
      ActUser = login.LoggedUser
      main.ShowDialog()
      End If

      DisposeApp()

    Catch ex As Exception
      ErrMsg(ex, "Error!", ErrorLogger.ErrMsgType.CriticalError)
      End 
    End Try
  End Sub
End Module

in debug mode everithing is OK. But in release mode when somewhere in application exception occurs my global catch in Main method doesn`t catch exception.

What is the problem please?

EDIT: unhandled exception from application is WebException thrown after failed web service call.

How can I handle this types of exceptions?

Answer 1

This is normal. There's an exception handler built into the Application.Run() method. It is disabled when you debug in order to make debugging exceptions easier. Without a debugger, the exception handler will display the ThreadExceptionDialog.

Add this statement at the top of your Main method to disable this exception handler:

   Application.SetUnhandledExceptionMode(UnhandledExceptionMode.ThrowException)