Server issues might be trying to persist; while people online are safe at the moment, it seems as soon as you log out, you're stuck. Was just in FH, went to switch character, logged in fine, but no characters work in any maps. Does that whole "Hey look at me I'm loading.... and loading... and loading.." while not producing any map lag that usually comes with getting into a map, both FH Vanilla and Custom. I've tried custom maps, Lonely, and The Grounds.
EDIT: Few friends are also reporting this issue, not just on custom maps.