Version 1.13.0 is available for download.
Changes in this version:
- Now the visibility level of individual photos can be controlled using the new "Visibility Level" located on the Metadata panel, in the "Piwigo Metadata" section.
- Fixed the "C stack overflow" error on Mac OS.
- Other minor improvements and fixes.
This is how you control the visibility level for individual photos: 
For a detailed list of changes, see the Piwigo Export Plugin home page.