Nothing, after to check your commands nothing. My error is the same on the beginning
steve@Server:~$ netstat -ptan | grep LISTEN | grep nginx
(Not all processes could be identified, non-owned process info
will not be shown, you would have to be root to see it all.)
steve@Server:~$ ss -pln | grep nginx
steve@Server:/root# chmod +x /root/permissions.sh && /root/permissions.sh
chmod: cannot access ‘/etc/letsencrypt/live/myid.duckdns.org/fullchain.pem’: No such file or directory
chmod: cannot access ‘/etc/letsencrypt/live/myid.duckdns.org/privkey.pem’: No such file or directory
chmod: cannot access ‘/etc/letsencrypt/live/myid.duckdns.org/chain.pem’: No such file or directory
chmod: cannot access ‘/etc/letsencrypt/live/angus.duckdns.org/cert.pem’: No such file or directory
steve@Server:~$ curl -ikL http://127.0.0.1:81/.well-known/acme-challenge/testHTTP/1.1 403 Forbidden
Server: nginx
Date: Sat, 26 May 2018 10:45:10 GMT
Content-Type: text/html; charset=utf-8
Content-Length: 162
Connection: keep-alive
X-Content-Type-Options: nosniff
X-XSS-Protection: 1; mode=block
Referrer-Policy: same-origin
403 Forbidden
nginx steve@Server:~$ grep 'acme-challenge' /var/log/nginx/le.*.log /var/log/nginx/le.access.log:127.0.0.1 - - [25/May/2018:12:45:10 +0200] "GET /.well-known/acme-challenge/test HTTP/1.1" 403 162 "-" "curl/7.47.0" "-" "127.0.0.1" sn="127.0.0.1" rt=0.000 ua="-" us="-" ut="-" ul="-" cs=- /var/log/nginx/le.error.log:2018/05/25 12:45:10 [error] 6305#6305: *1 open() "/var/www/letsencrypt/.well-known/acme-challenge/test" failed (13: Permission denied), client: 127.0.0.1, server: 127.0.0.1, request: "GET /.well-known/acme-challenge/test HTTP/1.1", host: "127.0.0.1:81"