I was very unhappy with Flyme 8.1.5.0A on my x8 so decided to revert back to 7.3.0.0G. I downloaded the update.zip and ran it for a clean install (deleted personal files). But at the setup screen (after connecting to wifi and before logging into Google) it wants me to enter a 4 digit "password". It can't be my latest pin because it's 6 digit. And it's not my old 4 digit pin. What the hell is it? Why would the phone want a password after a clean install? What can I do?