How to Fix Corrupted macOS Installer Errors

This updated guide examines How to Fix Corrupted macOS Installer Errors and organizes the essential facts, background, and practical takeaways in clear American English.

If you've recently tried to run your installer and suddenly get a message saying it is corrupt and unusable, don't worry! Keep reading the following simple way to fix the problem.

Why is the macOS installer broken?

Sometimes when using the macOS installer, you may get an error message that says something like:

This copy of the Install macOS Mojave.app application is damaged, and can't be used to install macOS.

( This copy of the Install macOS Mojave.app application is corrupt and cannot be used to install Mac operating systems .)

How to Fix Corrupted macOS Installer Errors � contextual image 1 — Error installing installer message

As Apple explained in a newly published support document, the likely cause of this "broken installer" error message is that the certificate expires. Fortunately, the repair is very simple.

How to fix a corrupted macOS installer

To fix a corrupted installer, simply reload the installer. Doing so will also ensure that you have all macOS updates that have been released since you created the original installer, meaning you won't have to update macOS as soon as the initial installation is completed.

You can find the latest official download links below for the 4 most recent versions of Apple's Mac operating system, all with new unexpired certificates:

macOS Catalina
macOS Sierra
OS X El Capitan
OS X Yosemite

To learn how to perform a clean macOS installation using a bootable USB method, please refer to the following articles:

Create a USB to install Mac OS X 10.10 Yosemite
Instructions on how to install (clean install) macOS Sierra 10.12 on Mac
Create a bootable copy of the OS X Mountain Lion installer

FAQ

What is How to Fix Corrupted macOS Installer Errors about?

It provides a structured overview of macOS, explains the main context, and highlights practical takeaways for readers.

Why does this topic matter?

Understanding the main concepts helps readers evaluate the issue, avoid common mistakes, and make better-informed decisions.

How should readers use this information?

Use the guidance as a practical starting point, confirm details that may have changed, and follow current product, safety, or security recommendations.