How to Fix “application is damaged, can’t be used to install macOS”

I recently tried to install Mojave on my Macbook Pro mid-2014. My first task was to try finding Mojave in the App Store, which turned out to be a problem. Searching for Mojave inside the App Store doesn’t return any result. Bizarre!

If you’re in the same boat, you might have to do what I did and find a direct link to Mojave from Apple’s website. I used this one:

https://itunes.apple.com/us/app/macos-mojave/id1398502828?mt=12

The link above will launch the macOS Mojave download page inside your App Store app.

I got the URL from the official Mojave OS page. If the link above doesn’t work go check if they updated the URL since I wrote this article.

It will probably take some time to download the Mojave installer, depending on your connection quality. It took me around two hours.

Note: if you’ve tried to install Mojave before, then you probably have an old (and invalid) installer on your hard drive. If you try to download a new one, you’ll get a misleading error prompt. To get around this, delete your old macOS Mojave file, and then click on the Download button in the App Store to get a new one.

New macOS Mojave installer doesn’t work?

After downloading a fresh copy of macOS Mojave, if you get the same, or a similar error message as before when you try opening the Mojave installer, don’t panic, try restarting your computer.

After restarting, hit up your Spotlight search (CMD + SPACE) and search for “Mojave” to quickly find the install file. Now double-click on it to open the Mojave installer window. It should look like this:

MacOS Mojave installer window

At least that (restarting) did the trick for me.

Troubleshooting

If you still can’t make it work, there’s a bunch help in this 9to5mac thread.