Started Getting Error 523

All websites hosted on one of our servers are giving this error: “Origin is unreachable Error code 523”. Everything was working fine previously, and no changes were made to the server.

523 means Cloudflare can’t reach your server.

Set the DNS records to “DNS only”, or pause Cloudflare, so requests go direct to the server and bypass Cloudflare. You can then see directly what the issue is on the server (or find out why Cloudflare cannot connect to it), fix it, then re-enable Cloudflare.