root@ubuntu-s-1vcpu-1gb-nyc3-01:~$ nginx -t
nginx: [alert] could not open error log file: open() “/var/log/nginx/error.log” failed (13: Permission denied)
2018/01/23 15:45:33 [warn] 1703#1703: the “user” directive makes sense only if the master process runs with super-user privileges, ignored in /etc/nginx/nginx.conf:1
2018/01/23 15:45:33 [emerg] 1703#1703: “worker_processes” directive is not allowed here in /etc/nginx/nginx.conf:6
nginx: configuration file /etc/nginx/nginx.conf test failed

Follow the path on my Droplet:

/var/log/nginx/error.log

2018/01/22 00:30:52 [emerg] 3686#3686: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:37
2018/01/22 00:32:21 [emerg] 3697#3697: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:37
2018/01/22 00:32:41 [emerg] 3705#3705: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:37
2018/01/22 00:32:58 [emerg] 3713#3713: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:37
2018/01/22 00:33:27 [emerg] 3725#3725: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:37
2018/01/22 00:36:44 [emerg] 3744#3744: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:37
2018/01/22 00:39:03 [emerg] 3796#3796: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:37
2018/01/22 00:39:31 [emerg] 3805#3805: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:37
2018/01/22 00:49:35 [emerg] 3834#3834: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:37
2018/01/22 00:52:08 [emerg] 3982#3982: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:37
2018/01/22 00:55:59 [emerg] 4071#4071: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:37
2018/01/22 00:58:03 [emerg] 4089#4089: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:37
2018/01/22 01:02:38 [emerg] 4107#4107: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:37
2018/01/22 01:02:48 [emerg] 4116#4116: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:37
2018/01/22 01:03:09 [emerg] 4195#4195: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:37
2018/01/22 01:11:34 [emerg] 4256#4256: invalid parameter “104.236.56.190” in /etc/nginx/sites-enabled/default:18
2018/01/22 01:11:51 [emerg] 4337#4337: invalid parameter “104.236.56.190” in /etc/nginx/sites-enabled/default:18
2018/01/22 01:18:04 [emerg] 4359#4359: invalid parameter “104.236.56.190” in /etc/nginx/sites-enabled/default:18
2018/01/22 01:22:36 [emerg] 4375#4375: invalid parameter “104.236.56.190” in /etc/nginx/sites-enabled/default:18
2018/01/22 01:25:28 [emerg] 4394#4394: invalid parameter “104.236.56.190” in /etc/nginx/sites-enabled/default:18
2018/01/22 01:26:11 [emerg] 4410#4410: invalid parameter “localhost” in /etc/nginx/sites-enabled/default:18
2018/01/22 01:27:01 [emerg] 4425#4425: unknown directive “accesslog/var/log/nginx/localhostaccess.log” in /etc/nginx/sites-e$
2018/01/22 11:23:26 [emerg] 1375#1375: unknown directive “defaultserver” in /etc/nginx/sites-enabled/default:42
2018/01/22 11:26:24 [emerg] 1758#1758: unknown directive “defaultserver” in /etc/nginx/sites-enabled/default:42
2018/01/22 12:06:06 [emerg] 1361#1361: unknown directive “defaultserver” in /etc/nginx/sites-enabled/default:42
2018/01/22 12:53:00 [emerg] 1401#1401: unknown directive “defaultserver” in /etc/nginx/sites-enabled/default:42
2018/01/23 12:57:46 [emerg] 1354#1354: unknown directive “defaultserver” in /etc/nginx/sites-enabled/default:42
2018/01/23 14:14:19 [emerg] 8712#8712: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:38
2018/01/23 14:15:16 [emerg] 8745#8745: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:38
2018/01/23 14:40:08 [emerg] 9067#9067: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:38
2018/01/23 14:48:12 [emerg] 9101#9101: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:38
2018/01/23 14:49:26 [emerg] 9122#9122: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:38
2018/01/23 15:07:03 [emerg] 9330#9330: “workerprocesses” directive is not allowed here in /etc/nginx/nginx.conf:6
2018/01/23 15:44:43 [emerg] 1382#1382: “workerprocesses” directive is not allowed here in /etc/nginx/nginx.conf:6
2018/01/23 16:43:59 [emerg] 1386#1386: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:38
2018/01/23 17:05:05 [emerg] 1859#1859: unknown directive “marcelo/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:38
2018/01/23 17:07:59 [emerg] 1881#1881: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:38
2018/01/23 17:20:59 [emerg] 1956#1956: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:38
2018/01/23 17:23:53 [emerg] 2014#2014: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:38
2018/01/23 17:32:20 [emerg] 2049#2049: unknown directive “/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:38
2018/01/23 17:33:28 [emerg] 2069#2069: unknown directive “./usr/share/nginx/html” in /etc/nginx/sites-enabled/default:38
2018/01/23 17:34:33 [emerg] 2087#2087: unknown directive “./usr/share/nginx/html” in /etc/nginx/sites-enabled/default:38
2018/01/23 17:41:42 [emerg] 2151#2151: unknown directive “./usr/share/nginx/html” in /etc/nginx/sites-enabled/default:38
2018/01/23 17:41:50 [emerg] 2166#2166: unknown directive “./usr/share/nginx/html” in /etc/nginx/sites-enabled/default:38
2018/01/23 17:54:59 [emerg] 2333#2333: unknown directive “./usr/share/nginx/html” in /etc/nginx/sites-enabled/default:38
2018/01/23 17:55:23 [emerg] 2352#2352: unknown directive “./usr/share/nginx/html” in /etc/nginx/sites-enabled/default:38
2018/01/23 18:00:06 [emerg] 2436#2436: unknown directive “./usr/share/nginx/html” in /etc/nginx/sites-enabled/default:38
2018/01/23 18:04:59 [emerg] 2515#2515: unknown directive “./usr/share/nginx/html” in /etc/nginx/sites-enabled/default:38
2018/01/23 18:18:45 [emerg] 2606#2606: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:38
2018/01/23 19:59:09 [emerg] 1365#1365: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:38
2018/01/24 00:39:09 [emerg] 1362#1362: unknown directive “root/usr/share/nginx/html” in /etc/nginx/sites-enabled/default:38

user www-data;
worker_processes auto;
pid /run/nginx.pid;

events {
workerconnections 768;
# multiaccept on;
}

http {

    ##
    # Basic Settings
    ##

    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;
    # server_tokens off;

    # server_names_hash_bucket_size 64;
    # server_name_in_redirect off;

    include /etc/nginx/mime.types;
    default_type application/octet-stream;

    ##
    # SSL Settings
    ##

    ssl_protocols TLSv1 TLSv1.1 TLSv1.2; # Dropping SSLv3, ref: POODLE
    ssl_prefer_server_ciphers on;

    ##
    # Logging Settings
    ##

    access_log /var/log/nginx/access.log;
    error_log /var/log/nginx/error.log;

    ##
    # Gzip Settings
    ##

    gzip on;
    gzip_disable "msie6";

    # gzip_vary on;
    # gzip_proxied any;
    # gzip_comp_level 6;
    # gzip_buffers 16 8k;
    # gzip_http_version 1.1;
    # gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;

    ##

    # Virtual Host Configs
    ##

    include /etc/nginx/conf.d/*.conf;
    include /etc/nginx/sites-enabled/*;

}