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
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.