[COMPLETED] 30 Mins Planned downtime Wed (07/15) @10 AM Pacific (5 PM UTC)
 

From the announcements thread:

On Wednesday morning (July 15th) at 10 AM Pacific time (5pm UTC), we plan to take Hero Lab Online, Realm Works, and our account/sales servers down for maintenance. We expect up to about 30 minutes of downtime, though it may be less.

UPDATE: We have encountered an unexpected complication and will be down a bit longer than expected. We hope to have services back up and running by about 11 AM pacific time (6 pm UTC). Sorry for the inconvenience.

UPDATE: HLO is live again.

UPDATE: Everything is now back up.