Mac App Is Damaged and Cannot Be Opened

Mac "App is damaged and can't be opened" message appears when macOS cannot verify the app's code signature or the download was corrupted. This guide covers everything you need to know about this topic, including common causes, step-by-step solutions, and answers to frequently asked questions.

Here are the key things to understand: Gatekeeper prevents the app from opening. Common with apps downloaded from the internet. App may not be signed or notarized by Apple. Download may have been incomplete or corrupted. Understanding these fundamentals will help you diagnose and resolve this issue more effectively.

The most common reasons this occurs include: App is not code-signed or notarized. Download was corrupted during transfer. Gatekeeper security settings blocking the app. Extended attributes flagging the file as quarantined. Identifying the root cause is the first step toward finding the right solution.

To resolve this, follow these recommended steps: Re-download the app from the official source. Remove quarantine: xattr -cr /Applications/AppName.app. Allow in System Settings > Privacy & Security. Right-click the app and select Open to bypass Gatekeeper. If these steps do not resolve the issue, consider consulting additional resources or a qualified professional.

This article is part of our Mac Error Codes collection on Error Codes Wiki. We provide comprehensive, up-to-date information to help you find solutions quickly.