Blueprint AD authentication error: "The authentication mechanism is unknown"

When authenticating against Active Directory, the following error message appears:

"Error: The authentication mechanism is unknown"

This error occurs when the Blueprint server attempting to authenticate against the Active Directory is in a domain that is not trusted by the domain that contains the Active Directory server. Blueprint authentication is performed by the Taskmaster component, which runs under the system account - this account is not trusted and therefore unable to authenticate against the Active Directory server's domain.

In order to make the authentication succeed, you must either add the Blueprint server to a domain that is trusted by the Active Directory server's domain, or change the Taskmaster to run under a user account that has permission to log on to the Active Directory server's domain.