Did a dirty flash over v12, wiped cache, installed Thunderstorms Kernel, and everything works fine. I needed to repair some bluetooth gadgets. ( I don't use S-Health or Always On Display)
So far, no Bugs, no Lag
Your problem isn't ROM related. Your data hasn't been encrypted, either. You need to look at the TWRP thread. There is lots of info about the data=0 issue. Be sure to install the latest, *patched* TWRP (which is actually linked inside the thre...