@mhasman If your Mojave installer was download before Oct. 14 2019 you need to download it again. This is a know issue with the cert for the installer expiring today. Here is a link to download Mojave - https://support.apple.com/en-us/HT210190

@luke.michelson Luke, thank you very much!

Today is 28 of October.
Unfortunately, Apple still did not fix the expired certificate issue on OS Mojave app.
""This copy of the Install macOS Mojave application is damaged, and can't be used to install macOS"

Can also confirm this.

10/29 - URL to download Mojave is now broken.

In Terminal, run:

softwareupdate --fetch-full-installer --full-installer-version 10.14.6

Posted: 10/29/2019 at 7:41 AM CDT by larry_barrett In Terminal, run: softwareupdate --fetch-full-installer --full-installer-version 10.14.6

This seems to be a Catalina only option/flag, but may be a good workaround for the time being.

Still not allowing any Mojave updates or Mac OS Installers. Seems like the links to the app store are broken.

@rrouleau as far as I can tell it is Catalina only. The softwareupdate tool is present in Mojave, but they are not currently listing any software (softwareupdate --list) as being available. I don't have any devices pre-Mojave, so can't really test it :)

For anyone needing to get a new installer of Mojave with the right certificates, you can use installinstallmacos.py. Rich Trouton has step by step instructions on how to use it here: lhttps://derflounder.wordpress.com/2018/02/27/using-installinstallmacos-py-to-download-macos-high-sierra-installers/t

You need to download the 18G103 build for 10.14.6 that is dated 2019-10-14.

@larry_barrett - Yes, the softwareupdate tool has been around for may generations of the macOS. --fetch-full-installer is the Catalina only flag that is new.

The command did work perfectly for my needs (to grab a full install of 10.14.6 with new cert) on a Catalina machine, so thank you for pointing out this new flag.

Where does the softwareupdate command store things? I don't see it in the regular /Library/Updates folder?

The current Catalina version downloads and installs into Applications by default.

I ran the script and got the DMG... mounted and copied the installer to my desktop but now JAMF Admin is zipping it when I try to upload to replace the expired installer... any idea why?

Maybe URL was broken because of Mojave Security Update 2019-001 release? Hope it is coming back soon

The App Store link is working again.

@J.Mukite @lohika On a different thread (one of the packagepocalypse ones) I saw users ongoing "damaged" report may be resolved by a reboot; give that a try and report back...

This link has links to the last 6 OS

https://www.macrumors.com/how-to/how-to-fix-a-damaged-macos-installer/

@Sterritt I actually have had some success with reboots. Thank you.

Just back date your system, I was tried backdate for 1 years and it's work!! :)