Unable to boot after 2020-005

I'm getting a diagnostics error after waiting a long time (40 to 50 minutes) when I reboot after installing 2020-005 for my Mac Mini. https://discussions.apple.com/content/attachment/24f118b5-a620-4860-a33c-0e7a5a716ac0


I did a Disk First aid after booting with cmd-R. Found zero issues and still didn't boot.


I tried removing the macOS Upgrade using an earlier post

boot with cmd-R

csrutil disable

reboot

cd /Volumes/My System/

rename "macOS Install Data" directory to "_macOS Install Data.sav"

reboot


I then get the black background and "not" symbol, https://support.apple.com/library/content/dam/edam/applecare/images/en_US/macos/Catalina/macos-startup-screen-prohibitory.jpg


I tried to boot holding Option and I only get

Mac Install (sorry, don't remember the exact name)

Recovery


Apple Hardware Tools (AHT) will not load with "cannot load 'efi/drivers/testsupport.efi'" error


Any advice on how to recover and successfully boot?


Posted on Sep 27, 2020 06:23 PM

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Posted on Sep 27, 2020 08:29 PM

Why dis you rename "macOS Install Data" directory to "_macOS Install Data.sav"???


Rename it back then...


1. Start up from macOS Recovery

To start up from macOS Recovery, turn on your Mac and immediately press and hold...

Command (⌘)-R

Install the latest macOS that was installed on your Mac.

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Unable to boot after 2020-005

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