You can make a difference in the Apple Support Community!

When you sign up with your Apple Account, you can provide valuable feedback to other community members by upvoting helpful replies and User Tips.

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

High Sierra macOS upgrade from Sierra - howto

I clicked the app-store link "get macos high sierra" in [support.apple.com/en-us/HT208969], then [Open] in the app store, but the popup box said: "This copy of the Install macOS High Sierra.app application is damaged, and can‘t be used to install macOS".

Why is apple's own file "damaged"?

How can I circumvent this obstacle?

Posted on Aug 22, 2020 9:43 AM

Reply
Question marked as Top-ranking reply

Posted on Aug 22, 2020 10:06 AM

Don't use Firefox for this link...


https://itunes.apple.com/app/macos-high-sierra/id1246284741?mt=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...


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... trash the Install MacsOS High Sierra.app in Applications then a new copy more recent version can be downloaded.

3 replies
Question marked as Top-ranking reply

Aug 22, 2020 10:06 AM in response to at-iMac

Don't use Firefox for this link...


https://itunes.apple.com/app/macos-high-sierra/id1246284741?mt=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...


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... trash the Install MacsOS High Sierra.app in Applications then a new copy more recent version can be downloaded.

Aug 22, 2020 4:37 PM in response to BDAqua

Yes, the problem was related to "expired Certificate" and was solved promptly, thank you very much!

I found further that, beside setting back the Date, one could also delete the [installInfo.plist] (?) from one of the folders associated with the macOS High Sierra app (under Applications)!

Solution was simple; the message about something being "damaged" was / is indeed misleading;

High Sierra macOS upgrade from Sierra - howto

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.