A request mapped to aspnet_isapi.dll was made within an application pool running in Integrated .NET mode. Aspnet_isapi.dll ...

A request mapped to aspnet_isapi.dll was made within an application pool running in Integrated .NET mode.  Aspnet_isapi.dll can only be used when running in Classic .NET mode.  Please either specify preCondition="ISAPImode" on the handler mapping to make it run only in application pools running in Classic .NET mode, or move the application to another application pool running in Classic .NET mode in order to use this handler mapping.