What does a 'stopsap fail http error http 1.1 401 unauthorized' error typically indicate in an SAP system?

This error signifies an authentication failure when the SAP system attempts to communicate with an external web service or application via HTTP. Specifically, the server requires authentication, and the SAP system is either not providing credentials, or the provided credentials are invalid. It means the SAP user or system user lacks the necessary permissions to access the requested resource.