Some Mac App Store Apps 'Damaged' Due to Expired Security Certificate

A growing number of MacRumors readers and Twitter users have been experiencing an issue with some Mac App Store apps displaying a "damaged" error when opened since late Wednesday. The issue has affected popular apps such as 1Password, Acorn, Byword, DaisyDisk and Tweetbot.

Damaged-Mac-App-Store-Apps

Mac App Store apps with a "damaged" error (Image: Graham/Twitter)

Mac users are prompted with this error message when opening Mac App Store apps:

“App Name” is damaged and can’t be opened. Delete “App Name” and download it again from the App Store.

Tweetbot developer Paul Haddad tweeted that the issue appears to be related to security certificates that expired on November 11, 2015, and he further speculated that the receipts now using SHA256 encryption may be causing problems with older OS X versions.

The issue, however, also appears to affect some users running OS X El Capitan, leading Haddad to believe that Mac App Store apps contacting Apple's servers simultaneously may be causing a "self inflicted DDOS on Apple’s receipt generation service."

Haddad says that rebooting your Mac on OS X 10.10 or later may resolve the issue, while some users have been forced to reinstall apps from the Mac App Store, disconnect from and reopen the Mac App Store or simply reenter their Apple ID password.

It appears that Apple has since set a new 2035 expiration date for the security certificates, per The Guardian, at least some for apps, but the issues are persisting for some. Apple did not respond to request for comment.

Update: Rene Ritchie at iMore has further explained what's causing Mac apps to report as "damaged" and what can be done about it.

Top Rated Comments

Razeus Avatar
66 months ago
Welcome to Tim Cook's Apple...

It Just Works is a thing of the past.
Score: 11 Votes (Like | Disagree)
pianojoe Avatar
66 months ago
Now, this is embarrassing.
Score: 8 Votes (Like | Disagree)
lysingur Avatar
66 months ago
I'm actually kind of glad that Apple isn't planning on making any cars. Oh, wait...
Score: 7 Votes (Like | Disagree)
Tiger8 Avatar
66 months ago
I said it before and I say it again, Apple is falling behind in the software department. The number of bugs seems to increase with every release for either OSX or iOS. They still haven't resolved the iCloud backup issue, they should be embarrassed.
Score: 7 Votes (Like | Disagree)
canesalato Avatar
66 months ago
And Scott Forstall was kicked out because he didn't apologize for Maps?
Score: 6 Votes (Like | Disagree)
konqerror Avatar
66 months ago
This is yet another Apple services fail. What happens if you're outside of Internet access, say you're going to give a presentation?

The cert is valid for 5 years, so they should make the system automatically refresh when the cert has a year or even 6 months left to go.

Even Microsoft's DRM is better than Apple's. For time-limited (corporate) activation, it starts trying to contact the activation server after a month, but will let you go 6 months without locking you out.
Score: 6 Votes (Like | Disagree)

Top Stories

m1 chip macbook air pro

Kuo: Redesigned MacBooks With Apple Silicon to Launch in Second Half of 2021

Tuesday November 24, 2020 7:53 pm PST by
Apple plans to release additional MacBook models with Apple Silicon in the second half of 2021, according to analyst Ming-Chi Kuo, as part of the company's two-year transition away from Intel processors across its Mac lineup. In a research note today, obtained by MacRumors, Kuo said that these MacBook models will feature a new design. Kuo did not specify which models these will be, but he...
2020 apple shopping event

Apple Offering Up to $150 Gift Card With Select Products on Black Friday Through Cyber Monday

Monday November 23, 2020 2:53 am PST by
Apple has announced its annual four-day shopping event, offering customers up to a $150 Apple Store gift card with the purchase of select products between Black Friday and Cyber Monday in the United States. The gift card values in the United States are as follows: $150 for 16-inch MacBook Pro $150 for 21.5-inch iMac $50 for 13-inch MacBook Pro $50 for MacBook Air $50 for iPhone SE,...
app store christmas icon

Apple Shutting Down App Store Connect From December 23 to December 27

Monday November 23, 2020 10:14 am PST by
Apple shuts down App Store Connect for a week around the holidays each year in an effort to give App Store staff time off from work. This year, App Store Connect will be unavailable from December 23 to December 27. With App Store Connect unavailable, Apple will not accept new apps or app updates, so all pricing changes and new app submissions need to be locked in before those dates for...
Target November Deals 1

Black Friday Spotlight: Target Begins Week-Long Sale With Deals on iPhone 12, Powerbeats Pro, and More

Monday November 23, 2020 8:07 am PST by
We've been tracking early Black Friday deals in our dedicated Black Friday Roundup, and in an effort to prepare our readers for the big shopping event we're highlighting sales store-by-store in the lead-up to November 27. Note: MacRumors is an affiliate partner with Target. When you click a link and make a purchase, we may receive a small payment, which helps us keep the site running....
mac mini macbook pro macbook air

Apple M1 Hands-On Comparison: MacBook Air vs. MacBook Pro vs. Mac Mini

Monday November 23, 2020 3:40 pm PST by
Apple's M1 Macs are out in the wild now, but ahead of the holidays, you might still be trying to figure out which one to pick up, either for yourself or as a gift for someone else. We've got all three of the new Macs available, so we thought we'd give MacRumors readers a hands-on overview of each machine in our latest YouTube video. Subscribe to the MacRumors YouTube channel for more videos. ...
max tech xcode benchmark m1 macbook

Video Demos Performance Differences Between 8GB and 16GB Apple M1 MacBook Pro

Monday November 23, 2020 2:54 pm PST by
All of the M1 Mac models use the same M1 chip, so the upgrade options are limited to SSD storage space and RAM. We haven't seen many comparisons that demonstrate the difference between a machine with 8GB RAM and the upgraded 16GB RAM option, but Max Tech today shared a video highlighting the performance between an 8GB MacBook Pro and a 16GB MacBook Pro. The video includes a series of...
new mac mini logicpro screen

M1 Macs Able to Run Up to Six External Displays Using DisplayLink

Tuesday November 24, 2020 6:53 am PST by
It is possible to run up to six external displays from the M1 Mac mini, and five external displays from the M1 MacBook Air and MacBook Pro, with the aid of DisplayPort adapters, according to YouTuber Ruslan Tulupov. This far exceeds Apple's specified limits on external displays with the M1 Macs. Apple's host of new M1 Macs are not capable of supporting as many external displays as their...
iPads black friday 20 sale feature

Apple Black Friday 2020: Best iPad Deals

Tuesday November 24, 2020 8:51 am PST by
Although we're still a few days away from the official launch of Black Friday, we've known for a few weeks that many retailers would be kicking off discounts ahead of November 27. Because of this trend, today we're tracking discounts across Apple's lineup of iPads, including the 10.2-inch iPad and 2020 iPad Pro. More sales are likely to appear as the week progresses, and when they do we'll update ...
13 16 inch macbook pro air trio

Reliable Leaker Suggests Redesigned MacBooks in 2021 Will Include Both Apple Silicon and Intel Models

Wednesday November 25, 2020 9:15 am PST by
Reliable leaker known as "L0vetodream" has today suggested on Twitter that redesigned MacBooks coming in the second half of 2021 will include models with both Apple Silicon chips and Intel processors. The brief Tweet came in response to a MacRumors article from earlier today, which outlined a report from Ming-Chi Kuo claiming that Apple plans to release redesigned MacBook models with Apple ...
ipad pro 2020 display

Black Friday Week Kicks Off With Up to $150 Savings on 2020 iPad Pro

Sunday November 22, 2020 2:37 pm PST by
As we head into Black Friday week, we're seeing some of the best deals of the season so far, with Amazon and Best Buy today discounting the latest iPad Pro models by up to $150 at the lowest prices we've ever tracked on these models. Note: MacRumors is an affiliate partner with some of these vendors. When you click a link and make a purchase, we may receive a small payment, which helps us keep ...