This morning, I upgraded my Ghost blog from 0.3.3 (the original droplet version) to 0.7.1.

• I stopped the Ghost service with sudo service nginx stop.
• I downloaded the ghost-latest.zip file.
• I removed the existing core folder and replaced it with the one from the compressed file.
• I also updated the index.js, Gruntfile.js, package.json, and the Markdown files. I also added the npm-shrinkwrap.json file.
• I deleted the node-modules folder with sudo rm -r node_modules, then ran sudo npm cache clear before running sudo npm install --production.
• I also verified that all files in destination folder were owned by the ghost user, as was the case prior.
• After a few hiccups, I was able to successfully start Ghost from the command line using npm start --production. My database was migrated from version 000 to version 004, and I got the message Ghost is running in production... in the console.
• I did not change the config.js in the Ghost main folder or the nginx configuration file. I know that nginx is still functioning, because I have multiple sites referenced in the configuration file, and they are all still running.

When I try to access the Ghost blog, I get a 502 Bad Gateway error. I've restarted both the nginx and ghost services and I still get the same error. Can anyone help?