Assuming you have followed the steps in the previous article to get your certificate, then you should be able to run this if your certificate is not expired.
sudo ./letsencrypt-auto renew
or to get a new certificate
sudo ./letsencrypt-auto -c /path/to/domain.com.ini -d domain -d http://www.domain.com auth
That may not happen if you have done fancy stuff on your website.
Google Chrome will not go to your website, so for troubleshooting use Firefox. Letsencrypt does not follow the same warnings that Google Chrome shows. It also does not care about HSTS headers.
You are going to have to reissue the certificate because renew will not work.
If you are telling Apache that http://www.domain.com should just be http://www.domain.com/owncloud, then anything placed on your server for letsencrypt will not be visible you need to temporarily disable that override.
Change DocumentRoot from
sudo vim /etc/apache2/sites-available/ownCloud-ssl.conf
sudo vim /etc/apache2/conf-available/owncloud-ssl.conf
The following is the contents of my domain.com.ini file.
rsa-key-size = 4096
server = https://acme-v01.api.letsencrypt.org/directory
text = True
authenticator = webroot
agree-tos = True
renew-by-default = True
email = firstname.lastname@example.org
webroot-path = /var/www/html
Since I set
/var/www/html, I need to create a logical link in
/var/www/ to the
.well-known directory so that the verification can work.
make logical link
ln -s -T html/.well-known/ .well-known
You can do
restart but both work.
sudo service apache2 restart