I have a MacMini from 2014.

It has an SSD which I formatted so now it has no OS on it. I tried internet recovery several times but every time I get the error "An Error Occurred While Preparing the Installation". I have tried it again and again after restarting and after formatting again and after using first aid too.

Then I resorted to installing MacOS Sierra using a Bootable USB. I used TransMac to format it and then restore it with the image file of MacOS I downloaded from the site:


Upon Boot it only showed the Internet recovery option nothing else. It didn't read my USB. I formatted the USB from disk utility with GUID partition scheme and then again chose the restore with image file option and again my MacMini did not read it.

  • I don't have any AppleStore in my country so I might not be able to get their help in person to reinstall.
  • I only have this one Mac - no other Macs to assist are rentable / borrowable in the immediate future for me

How can I install a macOS on my MacMini again of figure from the logs what the error in question means or understand when an OS install fails?

  • If you have an USB Sierra installer flash drive, you can use macOS to create .dmg file from this drive. You then can just use TransMac on a Windows machine to make an USB Sierra installer flash drive from this .dmg file. However, you can not do this from the .dmg file you downloaded from Apple by just using TransMac. You have downloaded a difference kind of .dmg file. Commented Apr 25, 2023 at 14:05
  • You might want to try my answer to the question "How to reinstalled macOS Sierra from USB Start-up Disk made using TransMac". Commented Apr 25, 2023 at 14:13


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