Let's Debug

Test result for dev.ccss.cz using http-01

A fatal issue occurred during the DNS lookup process for dev.ccss.cz/A.
DNS response for dev.ccss.cz had fatal DNSSEC issues: validation failure <dev.ccss.cz. A IN>: No DNSKEY record for key ccss.cz. while building chain of trust
A fatal issue occurred during the DNS lookup process for dev.ccss.cz/AAAA.
DNS response for dev.ccss.cz had fatal DNSSEC issues: validation failure <dev.ccss.cz. AAAA IN>: No DNSKEY record for key ccss.cz. while building chain of trust
A fatal issue occurred during the DNS lookup process for dev.ccss.cz/CAA.
DNS response for dev.ccss.cz had fatal DNSSEC issues: validation failure <dev.ccss.cz. CAA IN>: No DNSKEY record for key ccss.cz. while building chain of trust
Fatal
No valid A or AAAA records could be ultimately resolved for dev.ccss.cz. This means that Let's Encrypt would not be able to to connect to your domain to perform HTTP validation, since it would not know where to connect to.
No A or AAAA records found.
Debug
The IANA public suffix is the TLD of the Registered Domain
The TLD for dev.ccss.cz is: cz
Debug
The current status.io status for Let's Encrypt
Operational

Submitted Dec 17 07:43:28 2018. Sat in queue for 3ms. Completed in 6m5s. Hide verbose information.