It seems Alex had restarted the nether and made a few updates is what he said, waited a couple minutes and headed in survival, i wanted to disguised as a pig but it said "Unknown command" is there a reason it's down? Or a glitch while restarting? Occured around at 11:00pm In Pacific time zone (Utc-800)
I think its been turned off for a while after the maintenance. Just wait and it should be okay later.