Symptom

Upon activating MapifyPro, there is a fatal error: 

The logs display the following error message:

PHP Fatal error: Uncaught Error: Call to undefined function acf_localize_text() in /<path-to-mapifypro-plugin/lib/acf-mapifypro/admin/class-acf-mapifypro-locations-relationship-field.php

Explanation

This happens when the site is running an older version of the ACF Pro plugin.  MapifyPro does not require you the site admin to install ACF Pro, however it will prefer to utilize the standalone version installed by the site admin instead of the built-in version inside of MapifyPro. This is to prevent conflicts that occur when multiple copies of ACF Pro are running on the same page.

Since versions of ACF Pro older than 5.7 does not have the acf_localize_text() function, MapifyPro displays an error.

Resolution

Update your ACF Pro plugin to the latest version.