Run the following to fix:

cd /opt/eff.org/certbot/venv/local/bin
sudo ./pip install cryptography
sudo ./pip install zope.interface

Cryptography and zope interface are updated.

The following fixed the issue on AWS EC2:

unset PYTHON_INSTALL_LAYOUT

/root/.local/share/letsencrypt/bin/pip install --upgrade certbot

To fix:

sudo rm -rf /opt/eff.org/

Then run e.g. renew:

sudo /opt/letsencrypt/certbot-auto renew --debug

1. Download latest version:

curl -O https://dl.eff.org/certbot-auto

2. Mod script:

chmod +x certbot-auto 

3. Move location:

mv certbot-auto /usr/local/bin/certbot-auto

4. Generate SSL

/usr/local/bin/certbot-auto certonly --standalone -d example.com

5. New certificates will be generated and saved here:

/etc/letsencrypt/live/

1. Install mod_ssl and python

yum -y install mod_ssl python26-virtualenv

2. Change into /opt and clone letsencypt

cd /opt

git clone https://github.com/certbot/certbot letsencrypt

3. Run letsencrypt

/opt/letsencrypt/letsencrypt-auto --debug

Select relevant options when prompted.

4. Setup auto-renew

Auto-renew certificates every Sunday at 6pm:

crontab -e
# Renew Let's Encrypt certificates at 6pm every Sunday
0 18 * * 0 root (/opt/letsencrypt/certbot-auto renew && service httpd restart)