When trying to view an IIS webpage, you get this error:
HTTP Error 500.19 – Internal Server Error
The requested page cannot be accessed because the related configuration data for the page is invalid.
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”.
Error 500.19 suggests that the web.config file is locked / corrupt / unaccessible. This happens when it can’t be read – most commonly because some Windows feature or role service that is required, has not been installed OR the account used to run the IIS service or application pool doesn’t have read access to the directory containing the config file.
In my case it was that I hadn’t installed ASP.NET.
If these suggestions don’t help you solve the error 500.19, try to think about the specifics of your web application and what might be preventing the web config from not being readable. If you find something that fixes the requested page cannot be accessed because the related configuration data for the page is invalid error, that is not listed here, then please post it as a reply to help the next person!