Using this OS on an internet-connected machine exposes the system to unpatched vulnerabilities. It is strongly advised to:
| Issue | Solution | |-------|----------| | “This copy of the Install macOS High Sierra application is damaged” | Set system date via Terminal: date 0101010118 (Jan 1, 2018). Then retry install. | | USB not showing in boot menu | Ensure USB is GUID partitioned and formatted as Mac OS Extended (Journaled). | | Installation stuck at “Less than a minute remaining” | Wait up to 30 minutes; it’s verifying firmware. If stuck, restart and reinstall. | | Mac is too new (2019+) | High Sierra doesn’t include drivers. You cannot install it. | | Mac is too old (pre-2009) | Use a patcher (e.g., dosdude1’s High Sierra Patcher) – not covered here. | macos high sierra download dmg install
: If you are on Catalina or later, you can download it via Terminal using this command: Using this OS on an internet-connected machine exposes
shasum -a 256 /Applications/Install\ macOS\ High\ Sierra.app/Contents/SharedSupport/InstallInfo.plist | | USB not showing in boot menu