I have a VPS server that hosts 4 domains and many subdomains (quite a lot for my experiments ) and I have set up Let’s Encrypt certificates for most of them.
But I have just created a new subdomain and when I try to put a certificate on it fails.
I’m using Plesk 17.8.11 to manage all my domains/subdomains and to create Let’s Encrypt certificates.
It produced this output:
Invalid response from https://acme-v01.api.letsencrypt.org/acme/authz/125cwEO1_-KKqGiO2BobQ2jqXdRKnR3zetMcfc5-FXc.
Details:
Type: urn:acme:error:dns
Status: 400
Detail: DNS problem: SERVFAIL looking up CAA for apitpv.osumi.es
My web server is (include version): 2.4.10-10+deb8u12 as shown by dpkg
The operating system my web server runs on is (include version): Debian 8
I can login to a root shell on my machine (yes or no, or I don’t know): yes
I’m using a control panel to manage my site (no, or provide the name and version of the control panel): Plesk Onyx 17.8.11
For me (and DNSViz), the domain’s nameservers are returning SERVFAIL for a CAA query for that name. Among other issues which may or may not cause resolution to fail.
You’re using an older version of dig that doesn’t know what CAA records are, so it did something different: It looked up the A record for apitpv.osumi.es. and then the A record for “caa.”.
(dig can send queries for types it doesn’t support. 257 is the code for CAA. If it gets a positive response, the records are displayed in an encoded, non-human-readable format, but you know they’re there.)
It may have worked a few hours ago. It may work in some locations.
With luck, if a resolver queries a type that works first, it will cache the CNAME response, and then only make a CAA query for osumi.es. itself, which doesn’t fail.
You should open a support ticket to ACENS and explain them what is happening when trying to get a non existent CAA record for a subdomain that has already defined a CNAME record. Meanwhile… if you can add CAA records you could try to add a CAA record for your subdomain and try again (there is no need to remove the CNAME, just add the CAA record).