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?