“This Copy of the Install macOS Monterey Application Is Damaged” Fix

The “This copy of the Install macOS Monterey application is damaged, and can’t be used to install macOS” error almost always means your installer is old, not broken. Apple signs every installer with a security certificate, and older downloads stop working once that certificate expires. The fix is to delete the old installer and download a fresh copy, either from Apple or with the softwareupdate command in Terminal. If you can’t download a new copy, for example when you’re stuck in Recovery, you can temporarily set the Mac’s date back so the old installer runs.

Here are all the fixes, starting with the most reliable.

Why this error happens

• Expired certificate. This is the cause in most cases. Installers you downloaded months or years ago, or copied from another Mac or a USB drive, may carry a certificate that’s no longer valid.
• Wrong date on the Mac. If the clock is set far in the past or future, macOS may think a valid certificate isn’t valid. This is common after a battery replacement or a full reset.
• Incomplete download. A small “stub” installer (only a few MB) or an interrupted download can’t install anything.
• Old USB installer. A bootable USB drive made from an old download has the same expired certificate.

Fix 1: Delete the old installer and download a new one

1. Open Finder > Applications, and drag Install macOS Monterey to the Trash. Empty the Trash.
2. Download Monterey again from Apple. Apple’s How to download and install macOS page has direct App Store links for older versions.
3. Click Get in the App Store. If Software Update opens, click Download.
4. When the download finishes, the installer opens automatically. Click Continue and follow the steps.

The full installer is about 12 GB. If the new file in Applications is much smaller, the download is incomplete. Delete it and try again.

Fix 2: Download a full installer with Terminal

This is the most dependable method, because it pulls the full, current installer straight from Apple’s servers. It works on Macs running macOS Catalina or later.

1. Open Terminal from Applications > Utilities.
2. To see which installers are available, type this and press Return:
   softwareupdate --list-full-installers
3. Find the newest macOS Monterey version in the list, such as 12.7.6.
4. Download it with:
   softwareupdate --fetch-full-installer --full-installer-version 12.7.6
5. Wait for Install finished successfully. The new Install macOS Monterey app appears in your Applications folder.

If you only see newer versions of macOS in the list, your Mac may be too new for Monterey. Macs released after Monterey can’t install it.

Fix 3: Check the date and time

1. Open the Apple menu > System Preferences (or System Settings) > Date & Time.
2. Turn on Set date and time automatically.
3. Run the installer again.

In macOS Recovery, you can check the date by opening Utilities > Terminal and typing date. If it shows the wrong year, correct it using the command in Fix 4 with today’s date.

Fix 4: Set the date back to use an old installer

Use this workaround only when you can’t download a fresh installer, such as when you’re reinstalling from Recovery or using an old USB drive without internet.

1. Disconnect from the internet so the Mac doesn’t reset the clock automatically. Turn off Wi-Fi and unplug Ethernet.
2. Open Terminal (in Recovery, choose Utilities > Terminal from the menu bar).
3. Type this command and press Return:
   date 0101120022
   This sets the date to January 1, 2022, at 12:00. The format is month, day, hour, minute, year.
4. Quit Terminal and open the installer again. In Recovery, choose Reinstall macOS Monterey.
5. After the install finishes, turn the internet back on and set the date to automatic.

Outside of Recovery, you’ll need to put sudo in front of the command (sudo date 0101120022) and enter your password.

Fix 5: Recreate your bootable USB installer

If the error shows up when you boot from a USB drive, the drive was made from an old installer. Download a fresh copy with Fix 2, then recreate the drive. With a USB drive of at least 16 GB named MyVolume, run:

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

This erases the USB drive, so copy anything you need off it first.

Other messages you might see

Message	What to do
“The application can’t be opened”	Usually the same expired certificate. Download a new installer.
“macOS Monterey is not compatible with this Mac” or no Monterey option	Your Mac is too old or too new. Monterey supports Macs from roughly 2015 to 2022, depending on the model.
“An error occurred while preparing the installation”	Check the date first (Fix 3), then try a fresh installer.
Installer quits right away with no message	The download is incomplete. Check its size in Applications.

Frequently asked questions

Is my Mac damaged?

No. The message refers to the installer app, not your Mac. Your files and hardware are fine.

Can I still download macOS Monterey?

Yes. Apple still offers Monterey for Macs that support it, through the App Store link on Apple’s download page or the softwareupdate command.

Will changing the date cause problems?

Not if you change it back afterward. Some websites and apps won’t work while the date is wrong, which is another reason to stay offline until the install is done.

Does this fix work for Big Sur, Catalina, or Ventura?

Yes. The same error appears for other macOS versions with expired installers, and the same fixes apply. Just use that version’s name and number instead.