Getting "app is damaged and can't be opened" errors on your Mac? Here's the fix!

OS X El Capitan
OS X El Capitan

Apple seems to be having trouble with the security certificate for the Mac App Store this week and, while they've issued a new one, not every Mac seems to have picked it. So, if you're trying to launch an app and all you get is the "damaged and can't be opened" popup, here's what you need to do.

Note: This also works when a Mac App Store app is reported as being damaged for other reasons.

How to fix a damaged app that won't open on the Mac

  1. Reboot your Mac.
  2. Open your Applications folder either by using the Finder or searching in Spotlight.
  3. Find the damaged app and delete it.
  4. Enter your Mac user password to authorize deletion, if requested.
  5. Launch the Mac App Store.
  6. Make sure you're logged in. (You may need to re-enter your password even if you were previously logged in.)
  7. Go to the app you just deleted, either in your Purchased tab or by searching for it.
  8. Click on Install to re-download it.

I only had to re-enter my password to get some apps up and running again. Others I had to delete and re-install. All are working for me again. Hopefully yours are too!

Rene Ritchie

Rene Ritchie is one of the most respected Apple analysts in the business, reaching a combined audience of over 40 million readers a month. His YouTube channel, Vector, has over 90 thousand subscribers and 14 million views and his podcasts, including Debug, have been downloaded over 20 million times. He also regularly co-hosts MacBreak Weekly for the TWiT network and co-hosted CES Live! and Talk Mobile. Based in Montreal, Rene is a former director of product marketing, web developer, and graphic designer. He's authored several books and appeared on numerous television and radio segments to discuss Apple and the technology industry. When not working, he likes to cook, grapple, and spend time with his friends and family.

  • This doesn't appear to work for all apps, notably Divvy (which I didn't realize I relied upon so heavily until it broke yesterday afternoon). In this case, at least, an app update is required and is currently pending approval from Apple.
  • All you have to do is run: killall -KILL storeaccountd in a terminal. Sorted. via
  • If the app in question has an update waiting in the app store simply updating it will fix it. Worked for me with 2Do.
  • I had the entire App Store app not working at all here. No rebooting, file checking etc. would help for the past few weeks. The problem started with not allowing me to buy stuff or run updates and a week ago it ended up just showing a blank window. iTunes App Store has been working just fine as has iBooks. So it could not have been a connection problem on my end I think. In the mean time the App Store icon showed some 50 updates waiting, I knew it included the Yosemite B3. So I ran all tried procedures again, including DiskWarrior. No dice. I logged in as root and tried running the Store in there. Still no dice until I went back to my working account. The App Store took a long time to show content and the updates became active. I ran the B3 installer first and my updates are installing as I write this. All very strange. I am guessing the problem with apps reporting to be damaged was just the tip of the ice berg and a lot more was going on, of which I have been at the receiving end. I'll probably never know.......
  • has anyone gotten this to work with tweetbot?
  • I lost my newsstand application which comes with iPhone as a builtin application and I tried to download it again from the Apple Store but it's not working to re download it again and I can see the application in the notification settings but ofcourse you can't open it from there neither you can act on it from the notification settings I will appreciate if you could help me to get it back and I have iPhone 6 and I assume this happened after upgrading my phone to ios9 Sent from the iMore App
  • I've had this problem with my Kindle app, but managed to get it to work following a simple procedure I found elsewhere: don't get the replacement from the Apple Store but from the Amazon store instead!