As mentioned on EQIIPlayers as well as Official Announcements:
"Maintenance Notification: All EQII U.S. Servers Restarting
All U.S. based EverQuest II servers are being restarted in the next few minutes to address the issue with worlds becoming unavailable. We expect that this will be a short downtime. We apologize for any inconvenience this may cause, and thank you for your understanding."
~Gnobrin!
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