Fixes / macOS · Checked September 30, 2026

macOS "App is damaged and can't be opened": how to fix it

Short answer

macOS Gatekeeper shows this when it can't verify a downloaded app's signature. Most of the time the app isn't actually broken: its code signature is missing, invalid or doesn't match the file. If you trust the source, open Terminal and run xattr -dr com.apple.quarantine, then drag the app onto the window and press Return. If you don't trust the source, delete the app and download it again from the developer.

What this message means

Gatekeeper checks every app downloaded from the internet. It confirms the developer's signature, that Apple notarized the app, and that the files haven't changed since they were signed. When that check fails, macOS says the app is "damaged". Unlike the "unidentified developer" warning, this dialog usually has no Open button. The file may really be corrupted or tampered with. More often, though, the developer never signed or notarized the app, or signed it badly, or the download or unzipping changed a file. macOS attaches a quarantine attribute (com.apple.quarantine) to downloaded files, and that attribute is what triggers the check.

Common causes

Cause	How to tell
The app is unsigned, ad-hoc signed or not notarized (common with open-source tools, emulators and small indie apps)	It came from GitHub, a forum or a small developer's site rather than the Mac App Store. The developer's own help or issue tracker mentions this exact error, and other users report the same thing with the same version.
The download or unzip was incomplete or changed the files	The app's file size is smaller than the one listed on the download page, the download was interrupted, or you unzipped it with a third-party archiver. Downloading it again, or opening the file with Archive Utility, gives you a copy that works.
The app was modified after it was signed (cracked or patched software, plug-ins or files added inside the app bundle, or real tampering)	The copy came from somewhere other than the official developer, or you or an installer edited files inside the .app. A clean copy from the developer opens fine.
An App Store app has a stale or corrupted receipt or certificate	The app came from the Mac App Store and opened fine before, and the error started suddenly, sometimes in several App Store apps at the same time.
The Mac's date and time are wrong, so certificate checks fail	The clock in the menu bar shows the wrong date. Websites may also show certificate or privacy errors.

How to fix it

1. Delete the app and download a fresh copy from the official source

Drag the app to the Trash and empty the Trash.
Download it again from the developer's official website or the Mac App Store, not from a mirror or re-upload.
If it came as a .zip, double-click it so macOS's built-in Archive Utility extracts it.
Drag the app into your Applications folder, then open it from there.
If it still says damaged, check the developer's download page or help pages for a newer version or Mac-specific instructions.

2. Check Privacy & Security for an Open Anyway button

macOS Ventura 13 and later (System Settings). On Monterey 12 and earlier: System Preferences > Security & Privacy > General.

Try to open the app once, then close the warning with Done or Cancel. Don't choose Move to Trash.
Choose Apple menu > System Settings, then click Privacy & Security in the sidebar.
Scroll down to the Security section. If there's a message about the app being blocked, click Open Anyway. The button only shows up for about an hour after you try to open the app.
Enter your login password (or use Touch ID), then click Open in the dialog that appears.
If there's no Open Anyway button (common with the damaged message), use the Terminal fix below. Note: starting with macOS Sequoia 15, Control-clicking an app and choosing Open no longer skips this check.

3. Remove the quarantine flag in Terminal (only for apps you trust)

All recent macOS versions, including Sonoma 14, Sequoia 15 and later

Make sure the app is in your Applications folder and came from a source you trust.
Open Terminal (Applications > Utilities > Terminal, or press Command-Space and type Terminal).
Type xattr -dr com.apple.quarantine followed by a space. Don't press Return yet.
Drag the app from Finder onto the Terminal window to fill in its path, for example /Applications/Example.app, then press Return. If there's no output, it worked.
Open the app again. If you get a permission error, run the same command with sudo in front of it and enter your login password (the characters won't show as you type).

4. Reinstall a Mac App Store app

Apps installed from the Mac App Store

Restart the Mac. This sometimes clears a stale receipt check by itself.
If the error comes back, quit the app, then move it from Applications to the Trash.
Open the App Store, click your name at the bottom of the sidebar, find the app and click the download (cloud) button.
Open the reinstalled app from Applications.

5. Fix the date and time

macOS Ventura 13 and later. On older versions: System Preferences > Date & Time.

Choose Apple menu > System Settings > General > Date & Time.
Turn on Set time and date automatically and make sure the source is time.apple.com.
Check that the time zone is correct, then try opening the app again.

6. Re-sign the app locally (for unsigned apps on Apple silicon Macs)

Macs with Apple silicon (M1 and later), open-source or self-built apps that the developer doesn't sign

Run the quarantine command from the Terminal fix above first.
In Terminal, type codesign --force --deep --sign - followed by a space, drag the app onto the window, and press Return.
If Terminal asks you to install the command line developer tools, click Install and run the command again when it finishes.
Open the app. Only do this for software whose source you trust, because it replaces whatever signature the app had.

Next time, skip the search

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Still not fixed?

If a fresh copy from the developer still shows this message after you remove the quarantine flag, the app build itself is probably broken, or it doesn't support your macOS version or your Mac's chip (Intel or Apple silicon). Check the developer's release notes or issue tracker for a fixed version and report the problem there with your macOS version (Apple menu > About This Mac). For Mac App Store apps, contact the developer through the app's App Store page, or contact Apple Support if several App Store apps fail at once. On a work Mac, ask IT, because a device management profile may block apps that aren't approved.

Questions people ask

Is the app actually damaged?

Usually not. macOS uses the word "damaged" whenever an app's signature fails verification, which happens with unsigned or unnotarized apps as well as with corrupted or tampered files. A fresh download from the official source is the quickest way to tell which one you have.

Is it safe to run xattr -d com.apple.quarantine?

The command only removes the download flag so Gatekeeper stops checking that one app. It's safe for software you trust from its official source. It's risky for cracked or re-uploaded apps, because macOS will no longer warn you about them.

Why is there no Open Anyway button?

macOS often shows Open Anyway for apps from unidentified developers but not for apps it considers damaged. For those, the Terminal quarantine fix or a fresh download is the way forward.

Should I disable Gatekeeper with sudo spctl --master-disable?

It isn't necessary, and it turns off protection for every app on the Mac. On recent macOS versions you also have to confirm the change in System Settings. Removing the quarantine flag from just the one app is the better option.

Why did this start after I updated macOS?

Newer macOS versions enforce signing and notarization more strictly. Starting with Sequoia 15, Control-clicking an app and choosing Open no longer bypasses Gatekeeper, so older unsigned apps that used to open may now show this message until the developer ships a signed version.