The message "511 Network Authentication Required" typically indicates that the server you are trying to access requires authentication to continue. This means that you need to provide a valid username and password to gain access to the resource. The error code 511 is a HTTP status code that is defined in the HTTP/1.1 specification as "Network Authentication Required." This error code is typically returned by a web server when it requires a user to authenticate themselves before they can access the requested resource.
https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/511