An unexpected error occurred: SysCallError: (104, 'Connection reset by peer')

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:

groupeguerin.ca

I ran this command: certbot --apache certonly --domain groupeguerin.ca

It produced this output:

aving debug log to /var/log/letsencrypt/letsencrypt.log

Plugins selected: Authenticator apache, Installer apache

Starting new HTTPS connection (1): acme-v02.api.letsencrypt.org

Obtaining a new certificate

An unexpected error occurred:

SysCallError: (104, ‘Connection reset by peer’)

Please see the logfiles in /var/log/letsencrypt for more details.

My web server is (include version): apache 2.4.6

The operating system my web server runs on is (include version):CentOS Linux release 7.8.2003 (Core)

My hosting provider, if applicable, is:

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):
no
The version of my client is (e.g. output of certbot --version or certbot-auto --version if you’re using Certbot):certbot 1.6.0

Could you please share the log file?

I agree with @Osiris that it could be helpful to see the logs, but this error also suggests a likelihood that your server's network doesn't allow outbound HTTPS connections—do you think the server could be behind a firewall of some kind that restricts its ability to connect elsewhere on the Internet?