This happens when configuring or recovering via an internet-dependent installer path where legacy server architectures have shifted.
is a utility that downloads macOS installers directly from Apple’s servers. Download Mist from GitHub and run it on your Mac.
If you need to revive an older Mac, perform a clean installation, or set up a virtual machine, you will need a direct macOS High Sierra 10.13.6 DMG file.
Check the box to start the backup process. Step 2: Verify Your Drive Health
From the macOS Utilities window, select and click Continue .
Avoid third-party websites offering High Sierra DMG files, as they often contain malware or outdated versions. The best methods are official or semi-official: 1. The Official Apple Way (App Store/App Store Links)