I am also running into this same issue, although I hadn’t installed the plugin until after the 4.2.3 update was published.
The issue: Using shortcode `[pdb_search]’, the search box shows up with the drop down menu with no problem. After typing something into the box and clicking the search button the small grey spinning wheel appears, but no results show up, even though there is participants that match that search.
Thanks for the help!
Plugin Version 1.6.2.5
WordPress 4.2.3
