Yep (19:33) same message in that thread after I signed-out and in, Rebel, must still be processing that thread through Maintenance (MaintServerBYC).
Put up most of the site and work the part you want in the background :(
(or some such)
If this happened in the past 15 min. or so Site was just being updated (I got the chicken under the umbrella pic). Maybe that's it. Clear cache and try again. Things seem back to normal.