- Feb 22, 2017
"This copy of the Install macOS High Sierra application is damaged, and can't be used to install macOS." is the error message I receive when I choose to install macOS from the Disk Utility. The installer is over 5 GB so I have the full installer and I've used the UniBeast and the Public Beta method. This is the third time this has happened and I'm beginning to get annoyed. Any help out there?