I had an issue with Certbot (let's encrypt) which failed to reload nginx due to a non-ASCII character in a loaded config file.
E.g.: `Attempting to renew cert (domain.com) from /etc/letsencrypt/renewal/domain.com.conf produced an unexpected error: 'ascii' codec can't decode byte 0xe2 in position 762: ordinal not in range(128). Skipping.`
I found this character using `grep -r -P '[^\x00-\x7f]' /etc/nginx`.