mac os high sierra update blinking folder

I've removed the hard drive, put in an external case and plugged it into my old MBP and it doesn't even appear in Finder. The icing on this craptastic cake is I didn't verify my Time Machine backup - it must've failed because the last backup showing is MONTHS old. I can't download High Sierra using my other MBP because it's too old to be compatible (mid/late 2007) so download isn't even an option per Apple. I did manage to access the Apple Hardware Test and it said everything was OK. After the hoops to finally get access to disk utility (takes multiple attempts and each attempt takes quite awhile) there's nothing there - my hard drive isn't listed. I've tried internet recovery, set PRAM, rebooted holding various key combinations, etc. Ever since then all I get is the flashing folder with a question mark. The next day it was running slow then froze so I rebooted. I can't schedule an appointment with an Apple Genius as I don't reside in a country where Apple operates a retail store.Upgrade to High Sierra went fine on my MacBook Pro 15.4' Late 2011. Any help would be tremendously appreciated. I've tried to explain, as best I could, my issue with updating from Sierra to High Sierra and Mojave. Predictably, this fails too with everything going swimmingly until the final restart which brings you into the macOS High Sierra environment alas! the question mark folder again. I have also tried doing a clean install i.e formatting the SSD, reformatting it as APFS and then trying to install the new OS. Apple can make calls like this based on how many people are still using the software and how severe the security issues are. In November of 2020, Apple issued a security update for macOS High Sierra, even though it was three versions behind the latest release (Big Sur) at the time. I can confirm that High Sierra is installed by going into the Recovery Menu and checking the contents of the SSD.Īs I've said previously, I have tried installing from within macOS Sierra where the installation converts the SSD with a macOS Journaled filesystem automatically into APFS during installation – this has failed. Sometimes, Apple will update versions of macOS that fall outside of the two-year cutoff.

This is because my internal SSD is not recognised as a Startup Drive (it's missing from the Startup Drive Utility in Recovery Mode) after macOS High Sierra is installed. The error I get – a flashing folder icon with a question mark at startup – is the same with both methods. I have tried upgrading from within macOS Sierra and performing a clean install of the said operating systems from a flash-drive.

Each time, I have to reinstall macOS Sierra from Recovery Mode and restore my Time Machine backup. I've tried and failed to install both the macOS High Sierra and macOS Mojave beta multiple times. I am running macOS Sierra 10.12.6 on a MacBook Pro (15 inch, 2017) with 16 GB of RAM, a 256 GB SSD and Radeon 555 dedicated graphics.

Mac os high sierra update blinking folder