502 Bad Gateway error?

Is this likely a temporary issue? I’ve never had a page ‘load’ only to get an error: https://sci-hub.tw/10.0000/www.pep-web.org/ijp.078.0351a

Edit: A week later and still inaccessible =/ Is it all pep-web articles now? Getting this error on lots.

Edit 2: 14 days later and it works!