The Places library has been moved to legacy status. This means that it is no longer possible to enable it for new usage, and that it will be turned off in the future.

It has been replaced with the Places API.

To enable it, visit this page and click the “Enable” button.

After the new Places API is enabled, make sure to set the source of the autocomplete request to the new API on the settings page ( search section ) of the WP Store Locator plugin.