I don't know, but I'm guessing it has something to do with the GT 15th anniversary and imminent announcements regarding GT6 later this afternoon (in about 1.5 hours time) - the site is expecting a large influx of members and guests, and so facilities that put extra load on the servers are temporarily switched off to minimise the chances of disruption to the site in general...
If this is correct, I'm sure normal service will be resumed when the numbers of people on the site goes back down.
Smart move J 👍