This issue has been going on for several years and there are reports for macOS 10.14 Mojave and 10.13 High Sierra.
The update that brought the problem into my life was macOS Catalina Security Update 2020-001 and I am not alone.
Round 1 ❌: Usual SMC and NVRAM resets did not help.
Round 2 ❌: Created a bootable USB with macOS Catalina. Pressing ⌥ on boot and selecting the USB drive to get into that recovery mode to eliminate the possibilty of a faulty download of the stuck update which resides locally and might be used if recovery mode was started locally on the affected mac. Result was, update installed and on reboot the loading bar gets stuck right before finishing and remains in that state indefinitely.
Round 3 ❌: Booting into safe mode works. So was able to run Silent Knight and indeed an update to install showed up: 2020-001. Selecting Install updates in Silent Knight results in the same problem seen with the bootable USB: stuck loading bar after reboot right before the end.
Round 4 ❌: Re-download 2020-001 Catalina update while booted into Safe Mode and install from there. Same result: installs, reboot, stuck on loading bar right before the end.
Round 5 ❌: Safe Boot to uninstall Little Snitch, restart after uninstall, back at critial software update dialog. Still wifi, tethering, ethernet not working.
Round 6 ❌: Why not just connect to the wifi in the dialog about the critical software update shown on boot? Well, that is not possible. Entering the wifi password: no wifi connection, removing wifi password temporarily to omit user errors: no wifi connection, tethering to mobile: no wifi connection, connecting to ethernet cable: no wifi connection. You can’t just brick your users computer, show completely disfunctional dialogs how to get back to working state. And then tell your users: wipe everything. Also the wifi option not working has been experienced by others. Tried two different wifi setups at different locations to ensure the issue is not with the carrier providing the internet connection.
Round 7 ❌: Upgrade to macOS 11 Big Sur by via Recovery Mode by booting via ⌥⌘R which will install latest compatible macOS. Install went fine, but on reboot got stuck on the (by now) usual critical software update screen.
Round 8 ❌: use bootable USB with Catalina installer to boot into recovery mode. Open disk utility and format internal SSD. I did run migration assistant right away and as soon as that was finished was again stuck on the critical software update screen.
Round 9 ✅: repeat round 8 steps and skip recovery assistant during install to see if we have a working Catalina. Use migration assistant with deselected system files to avoid migrating the existing brick wall. This actually brought me back to working state.
Solution
Nuke SSD, install Catalina from bootable USB and migrate backup while desecting system files.
Shoutout to Apple for not only making bad hardware (the MacBook lineup from 2016 – 2019 is aweful) but also unreliable software.
Thoughts
The issue seems to be with a failed firmware update for the T1 / T2 chip and or a bootrom update going haywire.
An odd aspect is that the update got installed in december 2020 and only now mid january 2021 am I running into this wall. Apple released macOS 10.15.7 Security Update 2020-001 on 2020-12-14 with build id (19H114). Their own website lists the software update release date as 2020-12-16. Unsure if they had pulled the update for two days in december. If you know more let me know in the comment section.
A software update NEVER should cause problems of this kind. Catalina software update 2020-001 has cost me several days of time. The fact that Apple has no interest in getting to the root cause of this issue adds insult to injury.
Noch mehr Entropie 