I found this error installing for the first time in a certain server the IIS tools, specially the WCF feature.

The detailed error is:

HTTP Error 500.19 – Internal Server Error

The requested page cannot be accessed because the related configuration data for the page is invalid.
Detailed Error Information:

Module IIS Web Core


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”.

The solution is simple: to unlock IIS configuration for module settings, enter the following commands in an elevated PowerShell context.

Import-Module WebAdministration

Set-WebConfiguration `
-Filter "/System.webServer/modules" `
-Metadata overrideMode `
-Value Allow `
-PSPath "IIS:\"