How To Fix NGINX Error "502 Bad Gateway Error"

I got this error while opening URL of my site

After doing a simple Google search I solved the problem by adding two lines to Nginxconfiguration file /etc/nginx/nginx.conf 

http {
      .....
      fastcgi_buffers 8 16k;
      fastcgi_buffer_size 32K;
     .....
}


Thats it................