Invalid response from acme-challenge

[dbinfl]

Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. https://crt.sh/?q=example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.

My domain is:
crnctest.ddns.net
I ran this command:
acme.sh --issue -d crnctest.ddns.net --keylength 4096 -w /var/www/letsencrypt --key-file /etc/letsencrypt/rsa-certs/privkey.pem --ca-file /etc/letsencrypt/rsa-certs/chain.pem --cert-file /etc/letsencrypt/rsa-certs/cert.pem --fullchain-file /etc/letsencrypt/rsa-certs/fullchain.pem

It produced this output:
acme.sh --issue -d crnctest.ddns.net --keylength 4096 -w /var/www/letsencrypt --key-file /etc/letsencrypt/rsa-certs/privkey.pem --ca-file /etc/letsencrypt/rsa-certs/chain.pem --cert-file /etc/letsencrypt/rsa-certs/cert.pem --fullchain-file /etc/letsencrypt/rsa-certs/fullchain.pem
[Mon Oct 21 19:06:44 EDT 2019] Single domain=‘crnctest.ddns.net’
[Mon Oct 21 19:06:44 EDT 2019] Getting domain auth token for each domain
[Mon Oct 21 19:06:46 EDT 2019] Getting webroot for domain=‘crnctest.ddns.net’
[Mon Oct 21 19:06:46 EDT 2019] Verifying: crnctest.ddns.net
[Mon Oct 21 19:06:49 EDT 2019] crnctest.ddns.net:Verify error:Invalid response from http://crnctest.ddns.net/.well-known/acme-challenge/1bz5la7z0k57wUH1gA6c28kPTYvU7F7UBrahoru39hU [75.115.226.213]:
[Mon Oct 21 19:06:49 EDT 2019] Please check log file for more details: /home/acmeuser/.acme.sh/acme.sh.log
My web server is (include version):
Package: nginx
Version: 1.17.4-1~bionic
The operating system my web server runs on is (include version):
Ubuntu 18.04.3 LTS
4.15.0-65-generic x86_64 x86_64 GNU/Linux
My hosting provider, if applicable, is:
na
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):
openssh-client-ssh1/bionic 1:7.5p1-10
The version of my client is (e.g. output of certbot --version or certbot-auto --version if you’re using Certbot): ?? letsencrypt/bionic 0.23.0-1 ??

[_az]

Could you check your nginx configuration for this line:

listen 80 ssl;

You need to get rid of the ssl part.

If you don’t have that ssl part in your listen 80 line, then the problem may be that your port forwarding is misconfigured. External port 80 should map to port 80 on your server.

[dbinfl]

Hello!. Thanks for the prompt response.
It was the second point - misconfigured port forwarding. I had two entries in my router:
HTTP Server 80 80 TCP
HTTP Server 80 443 TCP
I removed the second entry and the certs creation was successful.
Thanks!
~dbinfl~