creation of Bootable USB

Is this the link you are using?:

How to Create and Use a Bootable Installer for macOS - Apple Support

The farthest back it goes is El Captain. If it doesn’t work, then try using another Mac to create it.

John Lockwood Level 6 (13,119 points)

Aug 21, 2019 8:01 AM in response to ednarcoleptic

In theory you download a full High Sierra installer from the Mac App Store. It is not listed anymore because Apple are encouraging people to use Mojave instead. There is an Apple KB article which however provides a direct link to the (hidden) item on the Mac App Store.

How to upgrade to macOS High Sierra - Apple Support

Scroll down to item 4 in the above document.

Of course as others have pointed out sometimes this results in only getting a 'stub' installer which is not suitable for then creating a bootable USB drive installer.

The way that I have found that is consistently able to download full installers is to run installinstallmacos.py as per


https://github.com/munki/macadmin-scripts

Ideally you run this on the Mac model you want to install on to.

If you are only downloading the stub installer, then you can try deleting the stub installer and also an App Store preference file. This may then allow you to download the full installer. Unfortunately I'm not able to find the link to this reference, nor do I know it will work since I haven't personally tried it yet.

You can also run the stub installer so it can download the rest of the installer. Just quit the app when it starts counting down for a restart.