When I try to upgrade to Mojave from Sierra and I get directed to the Apple store to get Mojave I get this message and can't upgrade? Im on a mac book pro from 2104. Any idea of what is happening here? I don't want to go to Catalina just yet.: This copy of the Install macOS Mojave application is damaged, and can‘t be used to install macOS.
MacBook Pro
That error message usually means that the App Store has detected a copy or partial copy of Install macOS Mojave.app in your Applications folder, why the error message can't say that we will never know.
Anyway open your Application folder locate Install macOS Mojave.app and move it to the Trash.
Empty the Trash.
Connect your mac to your router via cable rather than WiFi.
Restart your mac, go back to the App Store Mojave downloads page it should now say 'Get' or 'Download'.
Do not use the mac while it is downloading, and do not use any other devices that share the same internet connection
while the mac is downloading.
That error message usually means that the App Store has detected a copy or partial copy of Install macOS Mojave.app in your Applications folder, why the error message can't say that we will never know.
Anyway open your Application folder locate Install macOS Mojave.app and move it to the Trash.
Empty the Trash.
Connect your mac to your router via cable rather than WiFi.
Restart your mac, go back to the App Store Mojave downloads page it should now say 'Get' or 'Download'.
Do not use the mac while it is downloading, and do not use any other devices that share the same internet connection
while the mac is downloading.
You appear to have a bad download. If you are on a slow Wi-Fi connection, then use Ethernet instead. Try the download again. The Apple Store will not let you download Mojave, if your computer can run Catalina (which it should.) You may need to try a direct link:
macOS Mojave - Pick either one
https://itunes.apple.com/app/macos-mojave/id1398502828?mt=12
The Install macOS Mojave.app should be 6.05GBs in size when completely downloaded.
Is that what you are getting.
Have you tried it in Safe Mode. How to use safe mode on your Mac – Apple Support
do your un any third party apps that could be interfering with the download,
anti-virus apps, Little Snitch etc.
Have you checked for malware on your mac.
Tired this and it still comes up with the same message. This time I was actually able to download from the app store but when I tried to open and run the installer it came up with the same 'damaged' message???
Thanks for all your help. What worked in the end was disconnecting my external hardrive!! - should have done that anyway. Deleting the previous downloads of the Mojave Installer - I also a Mojave update that had been downloaded but was just sat in my applications folder. Then the download of Mojave worked and I am currently using it. Thanks again all.
Trying to Upgrade to Mojave from Sierra 10.12.6
