Iphone 6 plus restore error
dear sir and madam i am vendor of cell phones and i sold iphone 6 plus 16gb A1522 was with ios 8.3 from dubai and sold in africa republiq democretic congo and now customer came back withing few months that its showing error (-1) while restoring so please let me know solution.
i tried to restore it from iTunes with ios 8.4
iPhone 6 Plus, iOS 8.3