I was still getting the error message so asked on reddit - seems that the guy who created the site hasn't been 'seen' for weeks and doesn't seem to have done any maintenance in yonks, so I wouldn't hold my breath for timely trouble-shooting.
There is another site which scrapes redactle and other similar games
wordle-unlimited.io/redactle
IIRC, if redactle goes pfft completely, the owner of this site says they'll start generating new puzzles until it reappears