My server problem

hello everybody i have a problem with my server :
First i tried to join the server but i couldn't connect and there was a error message: minecraft authentication servers down.
Then i restarted the server and there was an other error message: minecraft java connection refused
And finally i restarted the server a last time and then the server crashed.
I hope someone can help me to solve this problem
Ps: We didn't used any plugins or mods and i used the right version.