“App Is Damaged” on Mac: Safe Checks Before Opening

Record the exact warning before changing anything

Check: Read the complete dialog. Separate “damaged” or “modified” from “developer cannot be verified” / “cannot be checked for malicious software”, and from “will damage your computer” / malware warnings. Record the app name, download URL and macOS version.

Expected result: You have the exact message and know which security branch applies.

If not: If macOS identifies malware or revoked authorisation, leave the app blocked and contact its developer through a separately verified channel.

Safe stop: Do not force open software macOS identifies as harmful, or disable Mac security protections.

Re-download a damaged app from its verified publisher

Check: For a damaged/modified app, keep it closed. Obtain a fresh installer from the publisher’s official site or the App Store. If the publisher provides a checksum, compare it. Replace only the application, keeping your documents and settings backed up.

Expected result: The newly downloaded, compatible build opens without a security override.

If not: If a fresh copy is also blocked, the source being official does not prove this build is safe or intact. Ask the publisher for a corrected, signed/notarised build.

Safe stop: Do not remove quarantine as a routine damaged-app repair.

Inspect integrity without changing security settings

Check: For a developer or support investigation, run the read-only assessment and verification commands below against the actual application path. Keep the exact output.

Expected result: Gatekeeper assessment and signature verification produce evidence you can share with the publisher.

If not: A rejection or signature verification error needs publisher investigation. An unsigned app also fails verification; this alone does not prove malware. Successful checks are not a guarantee of safety.

Use Open Anyway only for the eligible unsigned-app branch

Check: For a recognised app with a developer-not-verified or cannot-be-checked warning, try opening once, then inspect the "Supported security screen" command below. Consider Open Anyway only when macOS offers it and you have independently assessed the publisher and need for this app.

Expected result: The offered exception applies to this app, with the risk clearly understood.

If not: If no exception is offered, do not treat that as permission to bypass the warning. Use a supported build or contact the publisher.

Safe stop: A damaged/modified or malware warning is not interchangeable with an unsigned-app warning.

Prove the application works and preserve the result

Check: Open the clean supported build, check its version and perform one harmless operation with a copy of a document. If the warning persists, send the publisher the exact warning, macOS version, source URL and assessment output without private files.

Expected result: The app opens and the test operation succeeds with system security still enabled.

If not: Check the publisher’s macOS and Intel/Apple Silicon requirements. Use a compatible release, or leave the app closed while support investigates.