HTTP Error 500.19 – Internal Server Error with ASP.NET web on Windows 8 and IIS 8

I’m blogging this (again*) so next time I do a search I find my own post, it may also help you. I manage a few development VMs which I swear I have setup in the past correctly, but every so often I find one that’s got the following problem.

*Again: it’s in an older post in the trouble shooting part, but this time, the error is the title of the post to help indexing, as when I searched this time around, that post did not come up.

Scenario / Error

Windows 8 + IIS launching your ASP.NET web app, you get the following IIS error:

HTTP Error 500.19 – Internal Server Error
The requested page cannot be accessed because the related configuration data for the page is invalid.

Error Code 0x80070021
Config Error This configuration section cannot be used at this path. This happens when the section is locked at a parent level. Locking is either by default (overrideModeDefault=”Deny”), or set explicitly by a location tag with overrideMode=”Deny” or the legacy allowOverride=”false”.

Note the ‘locked at a parent level’, in the config error.

Solution

Turn on the Application Development Features. If they’re already on, then you have a different problem, there’s a few questions about ASP.NET IIS and 500.19 on Stack Overflow.

Enable IIS 8 App Dev Features

Hope this helps.