Here's my context: I am writing a WPF add-in for an application. This Application's main thread is unmanaged. I want to add a global exception handling system for this add-in to handle any unhandled exceptions. Here's what I've tried but not working: I cannot add a try-catch block to my Application.Run() code line. Because I am an add-in, that code fragment is in the application. System.Windows.Forms.Application.ThreadException is not working too. There might not be an WinForm Application exists. (WPF hosting in unmanaged code.) AppDomain.CurrentDomain.UnhandledException is not working too. Because maybe it's handled by the Application itself. It just doesn't enter my code. So, any ideas for this situation?