Over the last week or so I haven’t been able to load any conversations beyond the first page. It just sits there trying to reload but nothing ever happens. The only way I can get the popup to go away is to refresh the whole page (F5).
Seems like it fixed itself with no intervention on my part. I just checked the Inbox again today and it seems to be working, although the message counts (they were in the upper right by the navigation arrows) are now gone.