After much waiting, in just two days i solved all and the game server is online on the new dedicated server!
To log on to the server be sure to use the correct hostname/ip, that is: play.avengerscraft.com
If you see a headline/title that alerts you to update your dns, update them!
How to update/refresh/flush DNS:
On windows: Open CMD (from “run” under start or by press “windows key” + “R”) and type: “ipconfig /flushdns” without quote, and hit “enter”, done, just retry to connect on our server.
On MAC: Open terminal (from app search) and type: “lookupd -flushcache” or “dscacheutil -flushcache”, without quote, and hit “enter”, done, just retry to connect on our server.
On Linux: by default Linux do not offer dns chace service, you not need to flush dns.
Many plugins do not work, and the servers are all to upgrade, you can still play for the moment, nothing will change when i update the plugin and the server.
The world has not been reset and will not reset even after updates!