[Plugin: WP Favorite Posts] Loading entire page on click – conflict?

I have a million plugins loaded (plus custom post types), so I’m thinking this is a conflict of some kind. When I click “Add to favorites”, I see the loading gif, and then the page I’m on gets loaded within itself.

Check it out here: https://ceraweek.info/cw2012/session/opening-keynote

The favorite doesn’t get added to the list either (https://ceraweek.info/cw2012/my-agenda), whether I’m logged in or not.

Any ideas?

https://www.ads-software.com/extend/plugins/wp-favorite-posts/