It says The SIM card inserted in this iPhone does not appear to be supported. Only compatible SIM cards from a supported carrier may be used to activate iPhone. Please insert the SIM card that came with your iPhone or visit a supported store to receive a replacement SIM card.
Now when I plug in my iPhone, the only thing on its screen is the iTunes logo and the USB, indicating I should connect my iPhone to iTunes, and the slider for emergency calls. When I do plug it in, I get the message above.
My iPhone worked fine before I updated, I had no PIN lock on it, so it worked fine with my carrier. What can I do?
Many thanks in advance.