Similar story here. I use new posts regularly (from a desktop). Normally it has pages and pages. The other day it only had a couple, and I just assumed I'd accidentally pressed the "mark all as read" button. But I don't think I did, and it hit many of you, too. Maybe there's a back-end tool that does the same thing for everyone. Now I see multiple pages again according to the navigation in the bottom-right (4 pages) but clicking next to page 2 throws that error, nothing could be found. Page 1 links all work.