$ curl -i 'https://tools.wmflabs.org/extreg-wos/' HTTP/2 500 server: nginx/1.14.2 date: Wed, 15 Jan 2020 12:37:32 GMT content-type: text/html content-length: 291 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> <title>500 Internal Server Error</title> <h1>Internal Server Error</h1> <p>The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.</p>
It looks like the tool itself was still working yesterday (see T242719). But maybe this is a side-effect of work on that task? (Feel free to close as Invalid in that case.)