Occurs when an unhandled exception is thrown.
Assembly: System.Web (in System.Web.dll)
The exception that raises the event can be accessed by a call to the GetLastError method. If your application generates custom error output, suppress the default error message that is generated by ASP.NET by a call to the ClearError method.
If your Web application contains XML Web services, you cannot use the event for global exception handling of those services. The HTTP handler for XML Web services consumes any exception that occurs in an XML Web service and converts it to a SOAP fault before the being called. To handle XML Web service exceptions, build a SOAP extension to process Web service exceptions in a custom global exception handler.
For more information about how to handle events, see Consuming Events.