HTTP Error 500.19 and error code : 0x80070021

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

Module IIS Web Core

Notification BeginRequest

Handler Not yet determined

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".

Config File \?\C:\inetpub\wwwroot\APITeslin\web.config

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Solución:
Activar los características completas del IIS (World Wide Web Services)

Espero sea de su utilidad.