macOS may report that an application “is damaged and can’t be opened” when the download is actually corrupted, the signature is invalid, notarization is missing, or the package has been modified after signing. Treat the warning as a security signal rather than immediately disabling protection.
Recommended checks
- Delete the copy and download it again from the developer’s official site or the Mac App Store.
- Confirm that the app supports your macOS version and processor architecture.
- Compare the publisher’s checksum if one is provided.
- Inspect its Gatekeeper assessment and signature:
1 | spctl --assess --verbose=4 /Applications/Example.app |
- If the trusted developer documents that the app is unsigned, Control-click it in Finder and choose Open, then review the more specific prompt. On current macOS versions, Privacy & Security may also show an Open Anyway choice for that one app.
Do not globally disable Gatekeeper with spctl --master-disable. Do not recursively remove quarantine metadata from unknown, cracked, or modified applications. Those approaches suppress the mechanism that is warning you and do not prove the application is safe. If a legitimate developer’s package fails verification, report it to the developer so they can provide a correctly signed and notarized build.
