Hello, I have been flashing new roms and unlocking boot loaders for a while now. But I unlocked the bootloader on my phone and flashed some roms. One of them bricked my phone so I had to SBF back to stock jelly bean 4.1.2. I tried flashing another rom, but it wouldn't work and now my phone is stuck in fastboot and RSD Lite will not flash my phone back to stock. It stops at 5/27 and gives me the downgraded security version update tz version failed preflash validation failed for tz. I have installed the new drivers and reinstalled them, nothing works. Am I screwed because I downloaded the update after I flashed back the first time? I need help badly, can't figure it out.