When I input an endgame position via FEN (e.g. 8/6K1/1P6/2P5/8/8/5k2/7r w - - 0 1) and try to activate the endgame tablebase display, it remains blank for a few seconds and then shows the error message "Oops, sorry! The explorer is temporarily out of service. Try again soon!". This has been the case since roughly midnight UTC (in Firefox and Safari on Mac OS High Sierra).