My application uses Asp.net callbacks extensively.

Whenever any unhandled exception occurs after the control reaches to ICallback handler, such exceptions are propogated to client side callback error handler.

The problem is when an unhandled exception is raised before the program execution reaches to ICallback handler in a callback request, this event is not fired and nothing happens.

Is there any mechanism to let client side callback error handler know that some exception has occured.

I generally get this unhanlded exception whenever there is session timeout and my aim is to target all such unhandled exceptions which could raise before program execution reaches to ICallback handler and notify client side error handler about the error.