Documentation for manually adding the MVC classic diagram control to an application advises that a reference to MvcResourceHandler should be added to both the <httpHandlers> element and the <handlers> element in web.config. See the topic entitled "Adding Codes to the Web.config File" at http://help.syncfusion.com/asp.net%20mvc/diagram.
My (albeit limited) understanding is that the <httpHandlers> element is not required, and is in fact deprecated, if IIS is running in integrated mode. That's my conclusion after reading this Microsoft article: http://www.iis.net/configreference/system.webserver/validation.
The article's topic is actually the <validation> element. It states that <validation validateIntegratedModeConfiguration="false">, which is also recommended by the diagram documentation referenced above, is required if "you do not migrate your configuration but you want IIS to remain in Integrated mode (which is not advised) ..." It goes on to note that "IIS will no longer provide warnings for unsupported configurations when validateIntegratedModeConfiguration is false."
I would like to benefit from IIS configuration validation. Assuming I confirm that IIS is running in integrated mode, can I remove the <httpHandlers> section, and keep only the <handlers> section? The referenc to MvcResourceHandler is the only child in these sections of my web.config. If I can remove the <httpHandlers> section, can I also assume I no longer require <validation validateIntegratedModeConfiguration="false"> in <system.webServer>?
Thanks for your help.