gives a way to fix the issue by fixing permissions of a file, but it seems to be specific to the Nexus 4 as the Moto X does not have the file specified (or at least I can't find it).
The only other potential means to fixing this that I can find is to wipe the data partition, but that means I can't use my Nandroid backup, which means more work I'd like to prevent if possible. Of course, I still have both phone for a limited time, so if there's something I can do on the original phone that will make my backup usable, that would also work.
OK, so I have a Moto X Developer Edition (rooted, stock 4.4.2) that I recently requested a replacement for from Motorola. I took a full Nandroid backup on the old phone and restored it on the new one. After ironing out the initial kinks on the original phone (disabling Xposed and removing PIN) and trying again, the new phone looked to be at 100% until I tried setting my PIN up again. Whenever I try to go to the Security settings, I get an "Unfortunately, Settings has stopped" message. One suggestion I found was to re-flash system.img, which I did to no avail.