[Solved] new ckfinder does not load

Hi everybody,

I've installed ckfinder using the null parameter in order to make it work with ckeditor.
and it worked.
I've openned the ckfinder window (browse server button), and received the window with a popup message.
showing: "unknown error". the folder/file list is empty.

what to do?
attached is a screen shot.

I'm using .net 4.

Shahar.