This bug fix release fixes a single bug: PHP7 support. Back in WP Lynx 1.3.0, changes were made to to add PHP8.1, however, these were not PHP7 compatible. WP Lynx 1.3.1 moves to the latest adminKit which now supports PHP7 and PHP8.1.
You can grab the latest WP Lynx on the WP Lynx WordPress.org plugin page.
-John Havlik