2015 MBP does not boot with disk image from 2012 MBP
You've already figured out the cause of your crashes.

What you need to do is either one of two things:


Create a Time Machine Back Up of your old system and do a fresh install of macOS on your new machine and transfer everything using Migration Assistant
Do a fresh install of macOS on your new machine and using a network connection migrate all of your apps and settings over the network using Migration Assistant.


Keep in mind that if you are attempting to copy over an OS that is earlier that 10.10 it will NOT work on your Mid-2015 MBP.