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 appears to be rather widespread, affecting popular apps such as 1Password, Acorn, Byword, Call of Duty 2, DaisyDisk and Tweetbot.
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 expired receipts for authentication certification, and speculated that the receipts now using SHA256 encryption may be causing problems with older OS X versions.
Wonder if the receipt now being SHA256 is causing problems with old OS versions? pic.twitter.com/ozOssXWlBR
— Paul Haddad (@tapbot_paul)
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.
More details will be provided as they are known. Apple has been reached for comment.