I just purchased a used Nexus 4 online and it came with Android 4.2.2 (stock, as far as I can tell). The phone does have an unlocked boot-loader and is was rooted. I was able to un-root using supersu, but the OTA update to 4.3 still fails. It starts to install, then it just shows a screen that says "Error" with a dead robot.
Is there anything else I might need to do in order to allow this upgrade to go through? I don't care about keeping the unlocked bootloader or anything.