Let's Encrypt Verification & CodeIgniter

Thanks for the link, BilltheCat.

Although I already had something similar to what is suggested in the discussion in your link, I found one of the posts had a better and tidier version, thank you.

The problem appeared to end up being a (long-time identified, but still unfixed) occasional occurrence that has a work-around (and nothing to do with external access to the secret, which is the complaint given when it fails... something that bent my brain, because the secret was accessible from outside, even using a browser).

For anyone with the same problem, this discussion may be of interest : https://community.letsencrypt.org/t/lets...rl/81853/3