When reading and following the Mojave download link in the following knowledge base article:
https://support.apple.com/en-us/HT210190
and the related link:
I keep getting the following notification after a download: "This copy of the Install MacOS Mojave application is damaged, and can't be used to install MacOS" Is anyone else seeing this?
MacBook Air
Did you delete your old copy & restart? Maybe Safe boot to clear caches?
Safe Boot, (holding Shift key down at startup), does the problem occur in Safe Mode?
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 Mohave App in Applications, so expired Certificates are not expired.
Or... trash the Install MacsOS Mojave.app in Applications then a new copy can be downloaded.
Did you delete your old copy & restart? Maybe Safe boot to clear caches?
Safe Boot, (holding Shift key down at startup), does the problem occur in Safe Mode?
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 Mohave App in Applications, so expired Certificates are not expired.
Or... trash the Install MacsOS Mojave.app in Applications then a new copy can be downloaded.
Don't use FireFox for this link…
https://itunes.apple.com/us/app/macos-mojave/id1398502828?mt=12
If you get a corrupted message...
Naw, not damaged, it's just that you have an old copy already in Applications, Trash the Install MacsOS Mojave.app in Applications then a new copy can be downloaded.
Thanks for your prompt reply. I tried that first before posting, and it didn't work. I also tried your link and the original link and the one in the article I mentioned. I also tried another (old) installer app that I had on a different Mac, and got the same message when I tried it on the MacBook Air.
I'm trying to upgrade from 10.13.6 btw. The only thing that came to mind is I wonder if it's signed and the certificate has expired.
After deleting the old copy and restarting, I was able to download it again and this time it worked and successfully upgraded my machine. (I didn't have to resort to a Safe Boot.) Thanks!
Great news, take care my friend! :)
Damaged Mojave download (relates to HT210910)
