Q: Shutdown MacBook Pro Mid 2012

If you had a kernel panic, log and post it per these instructions:

https://support.apple.com/en-us/HT201753

Ciao.

A negative shutdown code may indicate a hardware problem. The precise meaning of the codes is not publicly documented.

If you haven't already done so, you can try resetting the System Management Controller. Otherwise, or if the reset has no effect, see below.

Make a "Genius" appointment at an Apple Store, or go to another authorized service provider. You may have to leave the machine there for several days.

Back up all data on the internal drive(s) before you hand over your computer to anyone. There are ways to back up a computer that isn't fully functional—ask if you need guidance.

If privacy is a concern, erase the data partition(s) with the option to write zeros* (do this only if you have at least two complete, independent backups, and you know how to restore to an empty drive from any of them.) Don’t erase the recovery partition, if present.

Keeping your confidential data secure during hardware repair

Apple also recommends that you deauthorize a device in the iTunes Store before having it serviced.

*An SSD doesn't need to be zeroed.