mid-2012 Macbook Pro Retina 15" won't recognize new adapter
You have the wrong power adapter.

The Mid 2014 uses a 60W adapter and the Mid 2012 uses an 85W.



See this page Find the right power adapter and cord for your Mac notebook on Apples's website for details

You can always use a power adapter with a higher power rating on a machine that requires less, but you can't use an adapter with a lower power rating on a machine that requires more.  In other words a MBP with a 60W power requirement will work fine with an 85W adapter, but a MBP with an 85W power requirement will not work with a 60W power adapter.

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