I'm not actually new here, but this is the first time I've seen this occurring, so I thought this might be the best place since questions of many types are accepted here.
What can cause instances to be greyed out and unselectable?
Haven Instance 1 Greyed Out?
Sun, 03/23/2014 - 12:59
How long was it grayed-out? I don't know, but occasionally instances of Haven reboot, and maybe that would cause the instance to be grayed-out?
(It used to be that all instances of Haven, and in fact the entire game, rebooted at 5:00 AM each day. But that no longer happens, and I hear that individual instances now reboot. I have never witnessed it myself.)