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Upgrade to Mojave giving problems.

I wish to upgrade from High Sierra OS to Mojave. I follow a link from Apple support pages to the App store and press the "Get" button for Mojave. The following warning comes up "This copy of the Install macOS Mojave application is damaged, and can‘t be used to install macOS."

Can anyone help me past this block?

Posted on Apr 10, 2020 12:35 AM

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Question marked as Top-ranking reply

Posted on Apr 10, 2020 7:09 AM

Plug in a USB and then open terminal and type:

sudo /Applications/Install\ macOS\ Mojave.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume

Replace MyVolume with your USB name in disk utility.

after it’s done, hold the option key on boot till you see the List of boot disks. Boot from the USB and select enter.

when booted from the USB in macOS Utilities head over to the top bar and click Utilities>Terminal and change the date to 24 Sept 2018 by typing:

date [mm][dd]HH]MM[yy]

where mm is month and MM is minute.

then click install macOS. It should work.

the reason for this is that Apple has stopped accepting the signatures used in Mojave and fail the verification, to encourage updating to Catalina. Thus you have to change the date for verification to succeed.

4 replies
Question marked as Top-ranking reply

Apr 10, 2020 7:09 AM in response to Ken W

Plug in a USB and then open terminal and type:

sudo /Applications/Install\ macOS\ Mojave.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume

Replace MyVolume with your USB name in disk utility.

after it’s done, hold the option key on boot till you see the List of boot disks. Boot from the USB and select enter.

when booted from the USB in macOS Utilities head over to the top bar and click Utilities>Terminal and change the date to 24 Sept 2018 by typing:

date [mm][dd]HH]MM[yy]

where mm is month and MM is minute.

then click install macOS. It should work.

the reason for this is that Apple has stopped accepting the signatures used in Mojave and fail the verification, to encourage updating to Catalina. Thus you have to change the date for verification to succeed.

Apr 10, 2020 7:22 AM in response to Ken W

The error message you mention usually means the App Store has detected a copy of the Install macOS Mojave.app on your mac.

Have a look in your Applications folder for that, move it to the Trash, empty the Trash.

Connect your mac to your router via cable not wifi.

Restart and try again.

Do not use your mac while it is downloading or any other device that shares the same internet connection.

Upgrade to Mojave giving problems.

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