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DiegoTeytey

macrumors newbie
Original poster
Jun 10, 2023
1
0
I have a MacBook Air 2015, and when I try to install macOS Sierra on it a bunch of problems happen. First, I went to install it and the problem was "An error occurred while preparing the installation. Try running this application again" Then I reset the Vram or something and now when I click continue after the system says that the Mac is going to be verified the installation doesn't begin.
 

Poncho

macrumors 6502
Jun 15, 2007
470
183
Holland
Your post just caught my eye and off the top of my head I think this is because there is a point in the installation process when your Macbook contacts the Apple servers to have the macOS Sierra installation verified. Unfortunately, the Apple servers (when I last checked a couple of years back) are no longer signing off/verifying macOS Sierra, deeming it to be an old OS. There is a work around. It's fiddly but have successfully used it myself. I might have posted the workaround in this forum a while back, so if I find it I'll post it here too.
 

Poncho

macrumors 6502
Jun 15, 2007
470
183
Holland
OK, it might be because the date on your Macbook is wrong at the time when you try to install OS Sierra.

Watch this short video.

 

Poncho

macrumors 6502
Jun 15, 2007
470
183
Holland
If this doesn't work then this is how I did a clean install of OS Sierra onto a fresh external drive.

I copied the ‘Install macOS Sierra' installer that I had archived onto the desktop of my Mac.

Then I went to System Preferences, then Date & Time. Then I clicked lock at the bottom and unclicked the box next to ‘Set date and time automatically’

Then I launched Terminal.

In Terminal I typed sudo date 0115124517

This set the clock on my Mac to to a date before the installer inside the OSX Sierra installer had expired.

I then disconnected the Mac from the internet

Now your Mac will show this date.

Only then did I launch the ‘Install macOS Sierra’ disk. Instead of getting an untrusted certificate warning it carried on as normal and gave me a choice of disks on which to install OS Sierra. I chose the frsh connected blank hard disk and ended up with a clean install of OS Sierra.

Only then should you connect your Mac back to the Internet and under Date & Time click the set date and time automatically box.
 
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