Today as also some months ago, we had on some of your services a Runtime Error:
Server Error in '/' Application.
Description: An exception occurred while processing your request. Additionally, another exception occurred while executing the custom error page for the first exception. The request has been terminated.
So the aspx error page could not be executed, because of an exception in itself.
I want to suggest you to create the static files
app_error.htm in your app root. I do so by having a
_app_offline.htm file, that I rename to
app_offline.htm to shutdown and disable my app. Also a
app_error.htm, that is presenting a nice static message, if there is an unplanned exception.
These files are static, to not involve ASP.NET and therefore not to have an exception when building an exception message.
To be more precise, this static app error page is not to replace the dynamic app error page. It is only returned, if the dynamic page fails. The app offline page is to disable ASP.NET processing permanently, not to only shutdown the current application domain instance.
It's just to be nicer than the default ASP.NET fallback message.