I've followed the instructions at https://certbot.eff.org/all-instructions/#debian-8-jessie-nginx but cannot install certbot:
sudo apt-get -t jessie-backports install certbot
Reading package lists… Done E: The value 'jessie-backports' is invalid for
APT::Default-Release as such a release is not available in the sources
Hints appreciated
Best Answer
did you follow instructions above that to enable backports? You need to add
to your /etc/apt/sources.list