I just tried this and got "Install failed with error: Update not found". A few days back I was searching around for how to download old macOS/OS X versions, so

I just tried this and got "Install failed with error: Update not found". A few days back I was searching around for how to download old macOS/OS X versions, so that I could run a VM to test my app [0]. For the first hour or so, all I could find was sites that linked to the official App Store downloads for the last 3 OSes, which didn't work. The page would open in the App Store app, I'd click "Get", and it would say that it wasn't found. This command unfortunately did the same, which makes me wonder if this is something to do with my Apple account, or maybe that they've taken down those downloads? What ended up working for me was dosdude's patchers: 10.12 Sierra: http://dosdude1.com/sierrapatch.html http://dosdude1.com/sierrapatch.html 10.13 High Sierra: http://dosdude1.com/highsierra/ http://dosdude1.com/highsierra/ 10.14 Mojave: http://dosdude1.com/mojave/ http://dosdude1.com/mojave/ 10.15 Catalina: http://dosdude1.com/catalina/ http://dosdude1.com/catalina/ These tools are meant for patching old OS X versions to run on unsupported Macs, but that wasn't the feature I needed. The important thing for me was their "Download" button, which downloads the installer directly from Apple's servers. It was a huge relief and I was finally able to test my app properly on older (virtualized) OSes using Parallels [1], which was even having a sale at the time (maybe still?). 0: my app is Recut, an automated video editor - https://getrecut.com https://getrecut.com - which supports back to 10.13 High Sierra 1: https://www.parallels.com/ https://www.parallels.com/