There seem to be a few miscellaneous conversion bugs left in an application that is now in production. I am unable to reproduce the errors.

I have a general purpose terminal error handler class that looks like this :

Friend Class ThreadExceptionHandler
    Public Sub Application_ThreadException(ByVal sender As System.Object, ByVal e As ThreadExceptionEventArgs)
        'Display Message for the user that the program is going south
        'Log the error

        Dim ex As Exception = e.Exception
        c = e.Exception.Message
        c = c & vbCrLf & "sender : " & sender.ToString
        c = c & vbCrLf & Environment.GetEnvironmentVariable("username") & " op " & My.Computer.Name
        c = c & vbCrLf
        c = c & vbCrLf & ex.ToString

        ' send myself an email with c in the boddy

        Application.Exit()

    End Sub


End Class ' ThreadExceptionHandler

This class is invoked as follows

        Dim handler As ThreadExceptionHandler = _
             New ThreadExceptionHandler()
        AddHandler Application.ThreadException, _
            AddressOf handler.Application_ThreadException

This approach works very well for most of the crucial errors, but for conversion errors that can happen anywhere and are difficult to reproduce, the information one gets is a bit sketchy.

I've been thinking of creating a static class with static properties that would give me clues about where error occurs and/what causes the error. The vales of those properties (last_method_called for example) would be set to the name of methods that I suspect and/or to the key.values (last_value_of_object_X) of certain objects.

I'm not too hot about this approach considering the dependencies all this would create. Is there a better approach to this kind of problem (other than avoid this kind of conversion problems early :) )?

Thanks in advance.