I had the misfortune to have to learn this (and how to fix it), so I’m documenting it here for the next person who does this to themselves.

We open on a Macbook Air 2012, updated to Sonoma 14.0 with OCLP. All is well. The machine runs…okay. It would probably be happier on Ventura, or Monterey, but because of reasons, I had updated it all the way to Sonoma so that there was no question of compatibility with the primary machine it was replacing while I was on travel.

I used the machine on travel, and definitely found that it’s not quite up to the task at Sonoma, to be dealt with at a different time. The real issue was that I did not update OCLP to 1.5.0 as soon as that release was out. This meant that when Sonoma 14.5 was available and the machine auto-updated…it broke.

Symptoms were that the trackpad and keyboard worked right up until login completed, and then did not work at all. Couldn’t run the browser to download the OCLP update, nada.

Normally, I’d shrug, erase the disk, and reinstall, but this was a bit of an issue because I had files that I wanted to get off this device. (Yes, I know, I should have had backups, but I worked on the plane while I had no internet, and I hadn’t had the machine up long enough for Backblaze to finish a new incremental before the software update ran.)

I tried a number of things: safe mode, doing a reinstall from Internet Recovery (we’d like to install El Capitan! sorry, your disk isn’t usable because I don’t recognize this filesystem)…and got nowhere. This was beginning to look bad.

Then I remembered I had a Carbon Copy Cloner backup on one of my externals. Hm. Thought this was the Air’s Sonoma, but seems to be Mojave from my Macbook Pro 2012. Trying to boot it can’t be worse than what’s going on now, so booted, held down option, and there was “Mojave” in the picker list. Chose it, crossed my fingers…and it booted!

I was able to download the latest OCLP (1.5.0), install it, run it, reinstall OCLP to the Air’s disk, and most importantly, reinstall the root patches. After that it was clear sailing: I shut down, restarted from the Air’s internal disk, and I was back in business on Sonoma 14.5.

The primary, most important lesson: run OCLP periodically and make sure it’s up to date! If I had done that as soon as I got home, the 14.6 upgrade would have Just Happened and everything would have been fine.

The secondary, also important lesson: disable automatic updates on your OCLP machines, and don’t update until you’ve verified that the most recent OCLP is installed and handles the version of the OS that you’ll be installing manually when you’re ready.

The third lesson: after you have a working install of whatever OS with OCLP, make a bootable backup immediately. If I’d had that to hand, it would have take 15-20 minutes to fix the issue. As it was, I spent almost a full afternoon trying to fix the installation before trying the Mojave backup that wasn’t even for the affected machine. (I think I used up my luck for a couple months on that one.)