Posts are not appearing in chat right now. When a user posts something, it often doesn't show up, as confirmed by various users. On my end, posts are staying green, indicating that they are not posting. Furthermore, new messages won't show up unless chat is refreshed. What is going on?
As shown by the status-completed tag added by Adam (a Stack Overflow developer), this issue appears to have been solved. I'm just posting this answer so the question doesn't stay in the Unanswered list.
We had some issues with chat following a SQL server upgrade, but I believe those have been resolved now.
-- Adam ♦