Insert a valid SIM with no Pin lock to activate iPhone
I am using Iphone 6 plus. My brother got it in Japan for me. The phone was working fine until I have restored it factory default last Saturday. The phone pop up with the message, "Insert a valid SIM with no Pin lock to activate iPhone" when I start the phone and when I set it up manually the phone displays the sim not supported message. Does anyone faced similar problem. Can this be fixed? Help needed.
iPhone 6, iOS 11.4