Help displaying custom fields info as points on Google Maps

Recently I have taken over the deployment of a WordPress site for a business that has multiple locations up and down the east coast. The previous developer had set up some custom fields to go with a certain page template, and also wrote some code enabling two of those fields (latitude and longitude) to display as points on an embedded Google Map, showing specific branch locations.

The previous developer had set up Apache to run on the local computer, which allows me to see a local version of the site. The map works flawlessly on the local version of the site. However, when the site is uploaded to a testing directory, I get an error which states:

Missing argument 2 for get_post_meta(), called in …locations-page.php on line 142 and defined in …post.php on line 1458

And the map also fails to load.

I’m running out of ideas, here. It’s not a wp-config.php issue as I have changed all mentions of localhost to the actual URL, and I don’t think it’s a syntax or code issue since it works fine locally. Any suggestions would be appreciated.

Page with error: https://75.98.173.128/~cb5k2015/wordpress/locations/