A fatal issue occurred during the DNS lookup process for hain3d.duckdns.org/CAA.
DNS response for hain3d.duckdns.org/CAA did not have an acceptable response code: SERVFAIL
No valid A or AAAA records could be ultimately resolved for hain3d.duckdns.org. This means that Let's Encrypt would not be able to connect to your domain to perform HTTP validation, since it would not know where to connect to.
No A or AAAA records found.