Fix the macOS “Is Damaged and Can’t Be Opened” Message

A Mac installer downloaded from the official Assist site may display “is damaged and can’t be opened” on first launch. If the disk image opens and copying completes normally, follow the text instructions included in the DMG.

Copy the app first

Drag the app from the DMG into Applications and wait for copying to finish. Use that installed copy, not the copy inside the disk image.

Remove quarantine for this app

Press Command+Space, type Terminal and open it. Run:

xattr -rd com.apple.quarantine "/Applications/选图汪本机搜图.app"

This removes the download quarantine flag from the named app without disabling system-wide security checks. Use it only for the official package whose source you have verified. No output and a new prompt usually indicate success; reopen the app from Applications.

Errors

For “No such file”, check the installed location and exact app name. Customized or renamed apps need their actual path. For “Operation not permitted”, the installer instructions provide:

sudo xattr -rd com.apple.quarantine "/Applications/选图汪本机搜图.app"

Enter your Mac login password; characters are not displayed while typing. Contact the administrator on a managed computer. Do not broaden the command to an entire disk or Applications folder.

If the DMG itself cannot open or the download is incomplete, download it again. Removing quarantine cannot repair a genuinely damaged file. For further help, provide your macOS version, chip, installer version and exact error.