To get either of those, you’ll need to use a Mac which can boot in that version of macOS.

So this iMac Pro, which shipped with High Sierra installed, can still download the Mojave installer, and that for High Sierra, but Sierra and El Capitan aren’t actually available despite being offered in the App Store. The basic rule appears to be that if you try to Get a version which is too old for that Mac to boot, then this is what you see when Software Update tries to get it for you: Those links do take you to pages in the App Store for those older versions of macOS, but whether they will deliver them to your Mac isn’t as simple, I’m afraid.

Last weekend, I outlined the preparations I’m making to upgrade to Catalina, and recommended that if you intended running an older version of macOS in a Virtual Machine or dual-booting, now was the time to ensure that you downloaded the installer for that old version.Īl Varnell kindly pointed out that, in addition to Mojave which remains available to all Macs capable of running Mojave (and sometimes even those which aren’t!) at present, access to previous installers is still supported in the App Store, giving the following links:

Tipico instal the last version for mac