www.kleos.ai has an AAAA (IPv6) record (2a01:7e01::f03c:91ff:fe08:e041) but a test request to this address over port 80 did not succeed. Let's Encrypt will prefer to use AAAA records, if present, and will not fall back to IPv4 records. You should either ensure that validation requests to this domain succeed over IPv6, or remove its AAAA record.
Get https://www.kleos.ai/.well-known/acme-challenge/letsdebug-test: EOF
Trace:
@0ms: Making a request to http://www.kleos.ai/.well-known/acme-challenge/letsdebug-test (using initial IP 2a01:7e01::f03c:91ff:fe08:e041)
@0ms: Dialing 2a01:7e01::f03c:91ff:fe08:e041
@171ms: Server response: HTTP 301 Moved Permanently
@171ms: Received redirect to https://www.kleos.ai/.well-known/acme-challenge/letsdebug-test
@171ms: Dialing 2a01:7e01::f03c:91ff:fe08:e041
@342ms: Experienced error: EOF
A test authorization for www.kleos.ai to the Let's Encrypt staging service has revealed issues that may prevent any certificate for this domain being issued.
Fetching https://www.kleos.ai/.well-known/acme-challenge/gFa30McHGorMFtbFd7BupCo9PlUEy6hYhh2RgVkfUK8: Connection reset by peer
Requests made to the domain
Request to: www.kleos.ai/2a01:7e01::f03c:91ff:fe08:e041, Result: [Address Type=IPv6,Server=,HTTP Status=301,Number of Redirects=1,Final HTTP Status=0], Issue: AAAANotWorking
Trace:
@0ms: Making a request to http://www.kleos.ai/.well-known/acme-challenge/letsdebug-test (using initial IP 2a01:7e01::f03c:91ff:fe08:e041)
@0ms: Dialing 2a01:7e01::f03c:91ff:fe08:e041
@171ms: Server response: HTTP 301 Moved Permanently
@171ms: Received redirect to https://www.kleos.ai/.well-known/acme-challenge/letsdebug-test
@171ms: Dialing 2a01:7e01::f03c:91ff:fe08:e041
@342ms: Experienced error: EOF
Request to: www.kleos.ai/139.162.143.226, Result: [Address Type=IPv4,Server=nginx,HTTP Status=301,Number of Redirects=1,Final HTTP Status=404], Issue:
Trace:
@0ms: Making a request to http://www.kleos.ai/.well-known/acme-challenge/letsdebug-test (using initial IP 139.162.143.226)
@0ms: Dialing 139.162.143.226
@172ms: Server response: HTTP 301 Moved Permanently
@172ms: Received redirect to https://www.kleos.ai/.well-known/acme-challenge/letsdebug-test
@172ms: Dialing 139.162.143.226
@518ms: Server response: HTTP 404 Not Found
A and AAAA records found for this domain
www.kleos.ai. 0 IN A 139.162.143.226
www.kleos.ai. 0 IN AAAA 2a01:7e01::f03c:91ff:fe08:e041
Challenge update failures for www.kleos.ai in order https://acme-staging-v02.api.letsencrypt.org/acme/order/5751349/14457327
acme: error code 400 "urn:ietf:params:acme:error:connection": Fetching https://www.kleos.ai/.well-known/acme-challenge/gFa30McHGorMFtbFd7BupCo9PlUEy6hYhh2RgVkfUK8: Connection reset by peer
The IANA public suffix is the TLD of the Registered Domain
The TLD for www.kleos.ai is: ai
3 Certificates contributing to rate limits for this domain
Serial: 431224733269223368047342161377033785034928
NotBefore: 2018-11-23 14:53:45 +0000 UTC
Names: [www.kleos.ai]
Serial: 382124233897801822331462984933872831954654
NotBefore: 2018-11-23 14:50:19 +0000 UTC
Names: [www.kleos.ai]
Serial: 364768744521332154112558332281969841417973
NotBefore: 2018-11-21 15:19:52 +0000 UTC
Names: [www.kleos.ai]
The current status.io status for Let's Encrypt
Operational