The problem occurs with the Availability Calendars module (https://www.drupal.org/project/availability_calendars). I first report a bug on this project (https://www.drupal.org/node/2449701). But in fact, the problem only occurs when I update CTools module from 7.x-1.5 to 7.x-1.6 (and, obviously, to 7.x-1.7).

Availability Calendars module provides a calendar field and a booking formlet field. On the node page, all is OK. On the Page Manager page, the booking formlet doesn't appear whereas the field is well added in the variant content.

Thanks for help.