The server have been updated to 2.5.1. If you encounter any problems, please contact us via ticket.

I would also recommend all players ( if they don't want to lose all their waypoints ) to save their minimap:
%appdata% -> .technic -> modpacks -> mcnewhorizons -> journeymap - ( just drag the journeymap folder e.g. to your desktop and then back to the mcnewhorizons folder after updating the client )

You can find the changelog from 2.4.0 to 2.5.0 Here.
You can find the changelog from 2.5.0 to 2.5.1 Here.

Your Arcturus Team.