Since you seem to be using facelets:
http://wiki.java.net/bin/view/Projects/FaceletsFAQ#I_m_getting_Duplicate_ID_Errors
SiSi'mon a écrit :
> We are getting errors on nearly every page now that we are using MyFaces
> 1.1.5. All seem to point to a duplicate ID problem but checking the xHTML
> there is no duplicate ID. This seems to be generated or something.
>
> Something seems quite mucked up. any ideas?
>
> ---
>
> SEVERE: Error Rendering View[/web/Information.xhtml]
> java.lang.IllegalStateException: Client-id : _id81 is duplicated in the
> faces tree. Component : idListForm:idPopupDataTable:_id81, path:
> {Component-Path : [C
>
> ---
>
