No media upload and no gallery in e-newsletter

Hi,
my issue is about insert media in newsletter.

As you can see in attached screenshot, in media gallery (standard) I have no problem. I can upload new images and then see the complete gallery.

But when I can try from e-newsletter wizard "boom", some strange whats happens : no images area show and if I try to upload new one I receive and error (attached).

Attached right media upload, error in newsletter plugin and a list of active plugin.

Note: this is a multisite installation.

Do you have some suggestions?