502 Bad Gateway nginx/1.10.3 (Ubuntu) after server reboot

Took over the website for a company. After resetting the server password and rebooting the server, the site is now giving a “502 Bad Gateway nginx/1.10.3 (Ubuntu)” error.

Checked the nginx error logs and getting several errors similar to this (replaced client IP and website name for privacy):

2018/09/02 19:09:09 [error] 4531#4531: *1 connect() failed (111: Connection refused) while connecting to upstream, client:, server:, request: "GET /favicon.ico HTTP/1.1", upstream: "", host: "", referrer: ""

Checked /etc/nginx/sites-available/default and this is the config (again, site has been changed for privacy):


     server_name; #PUT YOU$

     location / {
          proxy_pass; #PUT YOUR SERVER PORT HERE
          proxy_http_version 1.1;
          proxy_set_header Upgrade $http_upgrade;
          proxy_set_header Connection 'upgrade';
          proxy_set_header Host $host;
          proxy_cache_bypass $http_upgrade;

     listen 443 ssl; # managed by Certbot
     ssl_certificate /etc/letsencrypt/live/$
     ssl_certificate_key /etc/letsencrypt/live/$
     include /etc/letsencrypt/options-ssl-nginx.conf; # managed by certbot
     ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by certbot

server {
     if ($host = {
          return 301 https://$host$request_url;
     } # managed by Certbot

     if ($host = {
          return 301 https://$host$request_url;
     } # managed by Certbot

     listen 80;

     return 404: # managed by Certbot


Tried several suggestions found through community and can’t seem to get this to work. Any help would be greatly appreciated.


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Hi there,

Just came across this question in 2020. Here are some suggestions for anyone who might need this:

Here is a link to an answer on how to troubleshoot common Nginx problems:

And here is also a quick video demo on how to do that as well:

Regards, Bobby

Were you ever able to solve this issue? We are having the exact same problem and nothing seems to work