How to fix damaged app errors on Mac

Mac users have fewer errors to contend with than Windows but those that do occur are much more annoying. One common error we have seen quite a lot here at Dave’s Computers is ‘ This app is damaged and can’t be opened. You should move it to the Trash’. Today I’m going to show you how to fix it.

The error syntax will usually include the app name, so could read ‘Signal is damaged and can’t be opened. You should move it to the Trash’. The name would obviously reflect the app that isn’t working properly and tells you where to start in your troubleshooting.

Fixing damaged app errors on Mac

You have a few options when you see this error and I shall place them in the suggested order of priority when trying to fix them.

Reboot your Mac

A reboot is a useful first troubleshooting step to take with any Mac issue. It will purge RAM and reload all data from the OS and the app. If it was a corruption of the cache or app data held in memory it will all be gone and a fresh, hopefully uncorrupted copy, loaded.

Check for updates

Very occasionally, Mac OS will update and add an incompatibility that causes an app to error. If you have just updated Mac OS, it is worth checking for app updates too. They should download immediately but may need a helping hand. Use System Updates or the App Store to look for updates.

Reinstall the app

If there are no system or app updates and a reboot didn’t fix the error, your best bet is to uninstall the app and install a fresh copy. Something may have happened to the install files and be causing the error.

  1. Navigate to Applications on your Mac.
  2. Drag the app icon to the trash or right click and select Move to Trash.
  3. Right click the trash icon and select Empty Trash.
  4. Go to the App Store or developer’s website and download a fresh copy of the app.
  5. Install it as normal.

This should definitely stop the error from occurring and have you up and running again as usual. If it doesn’t, you might like to bring your Mac over to Dave’s Computers in New Jersey as it will need more work.

We use a tool called ‘xattr’ that can repair an installation but it requires a careful hand to use. Getting it wrong can seriously damage the app beyond repair and can cause your Mac to not respond in the normal way. Experienced users can try ‘xattr’ but I wouldn’t suggest it for casual users.

You would open a Terminal and type ‘xattr -cr /Applications/’ and hit Enter. This will remove all attributes linked to Signal and stop the error from happening. You would perhaps need to reinstall the app afterwards or will need to set up the app defaults depending on the app.

If you have any app errors and you don’t want to fix them yourself, the guys here at Dave’s Computers will be only too happy to help!