If your goal is to run your new ISO file in a virtual machine like VirtualBox or VMware, remember these optimization tweaks to prevent boot-loop errors:
sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/install_app Use code with caution. macos high sierra 10.13 6 iso download
Confirm the download. Once finished, a file named Install macOS High Sierra.app will appear in your /Applications folder. Method B: Downloading via Terminal (For Modern Mac Users) If your goal is to run your new