Again we can't play on our server the server is down for some reason. And I can not start it therefor I contacted the company where I rent the server why I can't start it and if they can solve it. Until then we have to wait.
The official Minecraft Authentication server is currently offline. Because of this you are not able to join any server that has the options on. My policy is to keep this option on as it is a extra protection against griefers and hackers.
I am looking into options to get this some sort bypassed without risking security. But until then you can't connect when the Authentication server is down.
Sorry for the inconvenience.
Because the company where I rent the server space is moving me to a new machine. The server will therefor get a new ip by using sv.citadelcraft.eu:25865 you will be ensured to have the best way back to the server. All that change is the machine where the server is on the map plugins and everything else will not be changed by this movement.
If you have questions post them on the forum or ask them me directly when I am ingame.