iATKOS | United Kingdom

I have an iMac14,1 that was experiencing booting issues with the latest Sequoia: basically it would hang very early in the boot process (Apple logo with loading bar at around 1%). I would only work after 2 or 3 (sometimes even more) forced shutdowns…

This iMac originally came with a 1 TB HDD, so I upgraded it with an NVMe SSD, but since those drives mounts on the motherboard I left the original HDD inside and connected just in case I needed some older version of macOS/OS X.

When I was able to boot into macOS it would give me the “You shutdown your computer because of a problem…” message along with the report. I copied that and gave to AI which said that the old internal HDD was probably failing and causing an error with the APFS probing or something like that… I really didn’t want to open my iMac again since it’s really time consuming and you have to buy new adhesive… but in the end (after some troubleshooting) I found out that it wasn’t the HDD that was bad, it was my OC configuration.

Basically I built OC from another Mac setting the Target Model to “iMac14,1” and it worked no problem. Then I opened the Open Core app on the iMac and discovered that if I set the Target Model to “Host Model” it would disable some options, specifically “3rd Party SATA PM”, “Disable Library Validation” and “Disable AMFI”. I just rebuilt OC by manually setting my Target Model to “iMac14,1” and now it works flawlessly.

Has anyone ever had a similar issue? I also have a 2012 Mac mini but I always built OC without worrying too much and it never gave me this problem… Hope this could be helpful to someone.