CKFinder , Initialisation error - Symbol error report

Hi,

I'm contacting you about an error, at first start of CKFinder.
An error raise, when i load the standalone page, and each others pages wich contain the CKFinder.

I'm in MVC2, 3.5.

I tested on an other website ASP.NET MVC2, and it works, but in our main mvc2 website not.

First, Why do i can't see the clear error message ?
And How do i can fix it ?

Thanks a lot,

Available for informations,

Giovanni.

Wygwam.