I got error 502, for around 4 to 4.5+ minutes.
It is now 9:52 PM UK time.
(yesterday, at around this time, maybe 10:18 PM ?, I also had error 502 for a couple of minutes or so)
Then a few seconds before it restarted ok, I got this:
Connection Problems
Sorry, SMF was unable to connect to the database. This may be caused by the server being busy. Please try again later.