I woke up to my unresponsive s8+ phone. Black screen and power button didn't work. I performed a soft reset (power + volume down button), phone rebooted, but never to my home screen, just the Samsung title and provider screens. After multiple reboot attempts, I receive a green screen with the message: ""Security Error: This phone has been flashed with unauthorized software and is locked. Call your mobile operator for additional support." I've been checking this forum for assistance but unable to figure out how to get the firmware I need for my phone using Odin (which I have installed on my PC - Win 10). I visited sammobile but US is not listed under Country/Carrier. Please help if you can. Thank you.