Certbot stores the configuration details needed by “certbot renew” in files in /etc/letsencrypt/renewal/. There was a bug in certain versions of Certbot that can lead to the web root being left out under certain circumstances, breaking future renewals.
So now you have to fix it.
“sudo certbot renew --cert-name gbcblog.com -w /var/www/html” might work.
If not, you could rerun the “certbot certonly ...” command you used to create the certificate originally.
You can also edit /etc/letsencrypt/renewal/gbcblog.com.conf in a text editor.