damaged copy of macOS High Sierra can not be used for installation
I click on "Get macOS High Sierra" on //support.apple.com/en-us/HT208969, App Store opens, I click on "Open" to get and install macOS High Sierra. I get "This copy of the install macOS High Sierra is damaged and can't be used". Any suggestions on how to upgrade to macOS High Sierra?
MacBook Air 13″, macOS 10.12