Actually just solved this. The theme was using ACF lite, and so I just commented out the middle row in the following code:
define( 'ACF_LITE', true );
//include_once('theme-utilities/includes/acf/acf.php');
include_once('theme-utilities/includes/acf/acf-config.php');
Seems to work for now, but if you have a better idea, please let me know!
