If a group widget is displayed more than once, the following JS error is raised :

Uncaught Error: Duplicate entity name "Ametys.form.widget.Group.Groups": Ametys.form.widget.Group.Groups and Ametys.form.widget.Group.Groups

The form being rendered is not displayed.

It will happens if an edition form containing a group widget has been reopened, or if a repeater wih several entries contains a group widget.