If you're on a U.S. server and planned on playing this morning, you may have to wait a little longer due to emergency maintenance.

All US realms will be undergoing Emergency Maintenance to resolve current In-Game issues at 5:00am PST (Pacific Standard Time). Downtime is expected to be approximately 2-4 hours. We sincerely apologize for any inconvenience this may cause. Thank you for your patience while we work to resolve these issues.

That means there's anywhere from a few minutes to a couple hours until the maintenance is complete. You can discuss the issue in this thread in our general forum.