There is a new issue since the last update the server has been disconnecting from the hive on a regular basis. Try to log in if you get the "no authentication possible" message go back to the server list and wait a few minutes. Your log in attempt will make the server try to reconnect to the hive. You should be able to log in a few minutes later. I am getting the same message when I try to connect or the message "you have been kicked from the server". We have reported the but and they are looking into it.
The server has no fully established connection therefor it can´t get lost. The server actually just makes a request and the response is the answer for the verification. What does your client show in the right top corner when you are in the menu? It should be a green line?