Fix "App is damaged and can't be opened" on Mac
macOS often shows the damaged warning for apps that are fine but unsigned or not notarized, because of a quarantine flag added when you downloaded them. Toolbox checks the app's signature and Gatekeeper status so you can see who made it, then removes the quarantine flag if you choose to trust it. Only do this for apps from a source you trust.
How to use Fix “App Is Damaged”
Open Fix "App Is Damaged" and drop the app onto the window.
Read the signature and Gatekeeper check to see who signed it.
If you trust the source, clear the quarantine flag and approve the admin prompt if asked.
Open the app again.
Questions about Fix “App Is Damaged”
Why does my Mac say an app is damaged?
Usually the app was downloaded from the internet and isn't signed or notarized in a way Gatekeeper accepts. The file is rarely corrupt; macOS is blocking it because it can't verify the developer.
Is it safe to remove the quarantine attribute?
Only if you trust where the app came from. Removing the flag skips Gatekeeper's check for that app, so check the signature first and redownload from the developer's site if you're unsure.
What does xattr -cr do on Mac?
It removes extended attributes, including com.apple.quarantine, from an app and everything inside it. Toolbox clears the quarantine flag for you and shows the signing details first.
What if the app still won't open?
The app may really be damaged or built for a different Mac. Download a fresh copy from the developer and check that it supports your macOS version.
Related tools
- Reset PermissionsUnstick an app’s Screen Recording, Microphone, Camera or other privacy access so macOS asks again.
- Login & Background ItemsSee what starts with your Mac and runs in the background, who made it, and turn off what you don’t need.
- Uninstall AppRemove an app together with the caches, preferences and data it leaves behind.
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