This is a forum for the Moto G5S, not the Samsung Galaxy S6.Hi
The issue mattdpollard had is exactly what I have right now.
I own a Samsung Galaxy S6 with LOS 17.1 for only 3 months. I did one weekly update fine but few weeks later the same process failed as explained above. I had to recover from a nandroid backup.
I try to solve that now but I didn't know this is a outlined issue. As JarlPenguin said this issue is now fixed, could you let me in what LOS version 17.1 or 18.1 and a link to it.
I don't think LOS 18.1 is reliable for Samsung S6. Could you confirm?
So, I stop my test here and will recover with my nandroid backup again.
I hope you have all these answers. Advice are welcome as I am not very skilled in this field.