Read from file for Google Maps pins is a feature that helps improve site speed for more than 200 properties on the map.

How it works:

Set the option to YES in Theme Options – Google Maps settings.

read from file

With this option set to YES – the following settings apply:

a. Pins.txt file inside theme folder must have writing permissions (755). Read more on how to set permissions here – http://codex.wordpress.org/Changing_File_Permissions

b. A cron runs daily to generate new pins for new properties.

Or you can generate manually and instantly from this Theme Options setting

read from file yes generate

If you have a multilanguage plugin installed, please read this help on how to make the pins.txt work with that.

http://help.wpresidence.net/2015/12/04/message-google-maps-settings-the-file-does-not-exist-or-is-not-writable/