Default Not registered on the network, but can be called!

Hello! Recently I removed the folder ESF gave it to the site and they did it but after receiving it says "not registered network" but the coverage is impossible to call and sms piasać, I would like to remove the inscription because he pisses me off how do I do that? And the second thing, I have a new ESF with Box and also have original copies of the initial android and if I can restore it to the original ESF is new with Box?