Hello,
Apologies, I thought the P.S. on the previous post was a mistake or typo. Server 1616 is not supposed to be live, yet, and players should not have access to it. This is why you are unable to load into the server. As you can see in this post,

https://forum-narutoen.oasgames.com/page/show-post-48714-1.html

the newest servers are 1567, 1598, and 1600, which go live tomorrow. 1616 should not be available for players yet. It is recommended that you try to find a different server to play on.
Thanks!