The authentication mechanism requested by the client is not supported
The WinRM client cannot process the request. The authentication mechanism requested by the client is not supported by the server or unencrypted traffic is disabled in the service configuration. Verify the unencrypted traffic setting in the service configuration or specify one of the authentication mechanisms supported by the server.
This error can be seen when Kerberos (or Negotiate when using custom credentials) authentication is disabled in the WinRM configuration on the machine being scanned.
Confirm that the appropriate authentication setting is enabled by executing the following command as an Administrator
winrm get winrm/config/service