TL;DR ==>
I bought a used Mac on eBay after verifying with Apple that yeah, no problem reverting it to the OS version I need to run on it. Couldn’t manage to do that on my own. Apple tech support is now on their 2nd week of trying to make this happen.
Hey folks! Lifetime Mac fan and evangelist here, been using Macs since the heydays of booting System 3 from an 800K floppy. I can touch ten working bootable Macs right here in my home office and I’ve never owned a Windows PC.
So, a handful of months ago my employer mandated that the minimum OS to remote in and work from home was MacOS X 10.14, and my reliable vintage-2011 MacBook Pros are too old to run it, so I obtained a used vintage-2018 MBPro from eBay, new enough to run that OS or anything newer but old enough to let me run 32 bit applications, a few of which I need. It already had 10.14 on it so I used the Migration Assistant and was up and running almost immediately.
Problem is, the only 2018 model I could find at that time had a mere half-TB SSD and I need more space if I’m going to make this computer my primary and not just a work-only computer. Well, I also always want an emergency computer, an identical box that can boot the exact same environment (right down to every setting and preference, every document, etc) that I can switch to if the primary box goes belly-up some day, so fast forward a few months and I jump on another eBay 2018 MBPro that has a full 2 TB SSD in it. I can move everything over to it and keep the existing one as emergency backup (booting it from external bootable daily backup if the main one needs to go into the shop someday).
Well, the new 2018 laptop was advertised as having Big Sur on it (that’s MacOS 11). I wanted to make sure there was nothing that would get installed on the laptop along with OS 11 that would keep me from erasing and formatting and installing MacOS 10.14 over it, so I contacted Apple tech support chat line and they verified: “Oh yeah, as long as that model is capable of booting 10.14, you can revert back to it, no problem”.
Ermm, not quite.
What I usually do is boot from the external drive (bootable backup of the current box) then format the internal and run the backup software in reverse. First problem: new laptop won’t boot from the external.
Okay, method two: set new laptop to boot in “Target Disk Mode”, which means other computers can attach it and access its drive as if it were an external drive instead of a computer. Attach it to the original 2018 in Target Disk Mode and yep there’s “Macintosh HD” from the new 2018 on the desktop… but so are two other volumes! I’m seeing a second one also called “Macintosh HD” in orange external-drive colors and a third one for Recovery. Disk Utility shows a drive containing a “Container” containing these three volumes. Confusingly, they all claim to be 2 TB capacity volumes.
Back into Apple Support chat. “Do I need to erase from the top, or just one of the volumes, or what?” Chat person says erase “Macintosh HD” and ignore the others. I do that, run Carbon Copy Cloner to push my Mojave (10.14) environment onto it, shut down, unplug, reboot new box. It won’t boot. Starts runnning something called “Internet Recovery”. Back to Apple Support chat. “Let it finish Internet Recovery, then I’ll walk you through the erase and install”.
Well, Internet Recovery fails at the end. Repeatedly. So laptop won’t boot from its own drive, won’t boot from external, and won’t boot from Internet Recovery. I try returning it to Target Disk Mode (by holding down “T” at boot) and reattaching it to the other 2018 laptop. This time I erase the entire SSD, format it APFS, and it makes a “Container” and within the container the new volume (just one this time). I again put Mojave on it.
It again won’t boot from it.
Apple switches to tel calls, escaling the ticket. “Well, looks like someone put an Activation Lock on it, contact previous owner”. I do. He apologizes and removes the lock by removing the Mac’s registration from his iCloud. Still won’t boot from anything, including Internet Recovery.
“Drive it to the nearest Apple Store”, telephone support instructs me. I do. I explain, and I bring old and new 2018 laptops, the bootable backup of Mojave, the Apple official Mojave installer, and cables. I show that the virtually identical (except smaller SSD) computer boots fine from either of the drives I connect with cables, but new one won’t. I explain I need Mojave and that’s why I was trying to erase and install over Big Sur.
I get email soon: “Come pick up your laptop, it’s ready”. I drive to store. They’ve installed Ventura on it. “Nope, I can’t use that, need 32 bit apps, ticket said to install Mojave, see here?” Oh yeah, sorry sir. Won’t be done before end of day, we’ll email you when you can come pick it up.
The original telephone Apple tech calls me next day to follow up. “I see from the notes it’s done. Did you get it yet?” I say no email to me yet. Decide to wait and see if they email me to pick it up before end of day. They don’t. I call next day to ask. “Oh, it was ready days ago”. The pickup date they cite is when I was first called because they’d erroneously put Ventura on it.
They have no notes about needing to erase Ventura and put Mojave on. The person on phone goes to read the original ticket. “Oh yeah I see they were supposed to put 10.14 on there. I’ll speak with the techs”. On hold music. “It should be ready tomorrow some time”.
They’ve all been very nice about it but I’m glad I wasn’t in any real hurry. Today is Day 8 of what should not be more than a few hours’ effort.