Trying to create a bootable High Sierra USB stick does not work

Question

Trying to create a bootable High Sierra USB stick does not work

After downloading the installer for High Sierra and following the appropriate procedure (that is in my case either using the Terminal or DiskMaker X or Tinker Tool System) in none of these cases the creation succeeds. Error message goes like this:

"The selected item does not appear to be a valid OS X Installer. It is lacking the subfolder "Contents/SharedSupport/InstallESD.dmg"

Of course the installer comes from the official App Store. I tried it several times with the latest High Sierra as well as the newest High Sierra Beta Version: Download from App Store, then quitting the installer and choosing the "install High Sierra" application in the applications folder.

I'd appreciate a hint whether this is a bug previously unknown or if the missing folder can somehow be obtained separately and being added to the installer package? Or is it my fault? Thanks for any help. If there are other ideas how to obtain a bootable installer USB stick, always very much appreciated!

MacBook Pro (Retina, 15-inch, Mid 2015), iOS 11.0.3

Posted on Oct 20, 2017 5:55 AM

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Answer 1

BobHarris

Level 9

56,933 points

Oct 20, 2017 6:03 AM in response to reinhardfromwiesbaden

Do you have the small 19MB version or the 5GB version?

The smaller version is used to check update your Mac's firmware so it will support an APFS bootable file system.

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Answer 2

azrael

Level 1

44 points

Oct 20, 2017 1:05 PM in response to reinhardfromwiesbaden

The full High Sierra installer (approx. 5GB) can be downloaded from the Mac App Store. By default it will download to your Applications folder and launch automatically. If you go through the installation process, the installer file will self-delete, but if you quit, the installer file will remain in your Applications folder.

I have successfully used the Terminal command described here:

How to make your own bootable macOS 10.12 Sierra USB install drive | Ars Technica

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Answer 3

Oct 20, 2017 2:28 PM in response to azrael

It remains a mystery to me - in the Mac App Store (in the sidebar) it clearly states the size of the File with 4.80 GB. But whenever I download it the outcome is a "install High Sierra" file in my applications folder being no larger than 19.9 MB.

I simply do not find a way to get my hands on the 4.8-GB-version. That probably is the only reason those diskmaker-apps are not able to create a bootable drive. Apple's help pages do not deal with this at all...

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Answer 4

BobHarris

Level 9

56,933 points

Oct 20, 2017 7:18 PM in response to reinhardfromwiesbaden

Launch the 19MB app and let it update your firmware so that your Mac will be capable of booting an APFS file system.

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Answer 5

Oct 20, 2017 9:01 AM in response to BobHarris

I have the 19.6 MB version - thanks for your post - but I do not know who to obtain the larger one anyway in case that would be required. If you could give me a hint there? I know that APFS is the new file system but frankly have no idea in which way that plays a role here....

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Answer 6

Oct 21, 2017 1:45 AM in response to BobHarris

Thanks again, I did that but it does not change a thing. I am even running the latest Beta: Version 10.13.1 Beta (17B35a). I'll ask Apple support via telephone later and will keep you posted, maybe they have an idea.

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