My notebooks access JSON data from a node/express setup which has Cors enabled ( sherlock.scalingo.io ). Curiously some notebooks work ( https://observablehq.com/@cjfpainter/idea-mining-the-mueller-report?collection=@cjfpainter/my-public ), whereas others which used to now don’t and give errors like this.

Access to fetch at 'https://sherlock.scalingo.io/headstart_find_keys?search=*' from origin 'https://cjfpainter.static.observableusercontent.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

I’ve checked the server code and rebooted, but remain baffled. All was well until about an hour ago from now 2019-08-12T23:00:00Z.

Could you share a link to a notebook where you reliably get CORS errors?

Hi there, genuine thanks for replying, but now the problem has gone away! Leaves me happier, a little more informed on CORS, and a bit embarrassed for calling you out in vain! My thanks and apologies therefore.

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