muscapaul wrote:
Please, edit you post to attach the locale...

The standard Newsletter Infusion does not allow guests to register so the Panel is not supposed to be shown to guests. That's why you get the errors.

A version of the Open Newsletter that should work is in the attachment. I think it works properly on the one site I made it available to. You have a go at it. If it works as it should I will prepare a formal release.