A validation request to this domain resulted in an HTTP request being made to a port that expects to receive HTTPS requests. This could be the result of an incorrect redirect (such as to http://example.com:443/) or it could be the result of a webserver misconfiguration, such as trying to enable SSL on a port 80 virtualhost.
@0ms: Making a request to http://zab.ordana.net/.well-known/acme-challenge/letsdebug-test (using initial IP 2a01:4f8:1c0c:80b3::2)
@0ms: Dialing 2a01:4f8:1c0c:80b3::2
@169ms: Server response: HTTP 400 Bad Request
zab.ordana.net has multiple IP addresses in its DNS records. While they appear to be accessible on the network, we have detected that they produce differing results when sent an ACME HTTP validation request. This may indicate that some of the IP addresses may unintentionally point to different servers, which would cause validation to fail.
[Address=2a01:4f8:1c0c:80b3::2,Address Type=IPv6,Server=Apache,HTTP Status=400] vs [Address=195.201.252.224,Address Type=IPv4,Server=Apache,HTTP Status=301,Number of Redirects=1,Final HTTP Status=404]