Got a server running with the following: Vestacp, Nginx, Let's Encrypt, PHP-fpm, @ DigitalOcean.
I have around 10 WP sites currently running on it, and so far I have had no problems at all enabling SSL. But all of sudden I get this error when trying to enable Let's Encrypts SSL:
Invalid response from
http://example.com/.well-known/acme-challenge
I found a couple a threads mentioning that I could be because I was missing a file Letsencrypt.pipe - and I could not find the file, so I followed the instructions and created where it was supposed to be - and it seemed to work great for the next website I enabled Let's Encrypt on.
But now 2 sites later, I'm again unable to enable SSL and get that error again.