When I select the macOS High Sierra to install, a dialog box opens that states, "This copy of the Install macOS High Sierra application is damaged, and can't be used to install macOS." How can I get a copy that is not damaged so I can update my system?
iMac, macOS 10.12
If you get a corrupted message...
Naw, not damaged, it's just that you have an old copy already in Applications, there are 2 cures...
If you’re short of bandwidth or data… Disconnect from the Internet & set the Date back to 2014, then you can run the Install MacsOS High Sierra App in Applications, so expired Certificates are not expired.
Or...As dialabrain says trash the Install MacsOS High Sierra.app in Applications, empty trash & restart, then a new copy of a more recent version can be downloaded…
Don't use FireFox for this link, it’ll offer strange erroneous errors…
https://itunes.apple.com/us/app/macos-mojave/id1398502828?mt=12
Delete "Install macOS High Sierra" from the Applications folder. Download again while in Safe Mode.
Trouble installing macOS High Sierra
