Mac OS High Sierra
I'm trying to get my old Mac OS up to date, and I need to install High Sierra so that I can be able to install the latest OS. When I try to download the install, I get this error message:
"This copy of the Install macOS High Sierra application is damaged, and can‘t be used to install macOS."
Where can I get an undamaged version?
iMac 27", macOS 10.12