So!,
letsencrypt renew output
Domain: www.domain.com Type: unauthorized Detail: Invalid response from http://www.domain.com/.well-known/acme-challenge/WLpdvugG3YzC53RTrZMJcYWsRqcj64vWLw43HNBkMN6:
nginx error log
66.133.XXX.XXX - - [11/Feb/2017:09:33:20 +0100] "GET /.well-known/acme-challenge/WLpdvugG3YzC53RTrZMJcYWsRqcj64vWLw43HNBkMN6 HTTP/1.1" 404 247 "http://www.domain.com/.well-known/acme-challenge/WLpdvugG3YzC53RTrZMJcYWsRqcj64vWLw43HNBkMN6" "Mozilla/5.0 (compatible; Let's Encrypt validation server; +https://www.letsencrypt.org)"
“Somehow” my domain root has changed.
I had to take a look at /etc/letsencrypt/renewal/domain.com.conf and fix some paths… 🙂