Apple Responds to Developers Regarding Expired Mac App Store Security Certificates

Last week some users and developers experienced an issue that displayed a "damaged" error when attempting to open select apps from the Mac App Store, including popular apps like 1Password, Tweetbot and Byword. Today, Apple has sent an email to developers explaining what happened and how to fix their apps.

CUDcjswUsAAiKe-
In the email, which developer Donald Southard Jr. shared on Twitter, Apple explains that the company issued a new security certificate for the Mac App Store in September in anticipation of the expiration of the old certificate. The new certificate used a stronger SHA-2 hashing algorithm instead of the old SHA-1 algorithm. Hashing algorithms are used by certificate authorities to sign security certificates.

However, two issues caused users to experience errors when starting up apps. The first issue, according to Apple, is that there was a caching issue with the Mac App Store that required users to restart their computers and re-authenticate with the Mac App Store to clear out the old cache. Apple says it's working on a fix for this in an upcoming OS X update. The other issue is that some apps were running an older version of OpenSSL that didn't support SHA-2. Apple says it replaced the SHA-2 certificate with a new SHA-1 certificate last Thursday night.

Finally, Apple says that "most of the issues are now resolved", but that some apps might still experience problems if the apps make "incorrect assumptions" about the Mac App Store's security certificates. Apple asks developers to make sure their code adheres to the Receipt Validation Programming Guide and to resubmit apps for expedited review if necessary. The AppleCare support team has also been briefed with the latest troubleshooting information for users.

Popular Stories

iOS 26

15 New Things Your iPhone Can Do in iOS 26.2

Friday December 5, 2025 9:40 am PST by
Apple is about to release iOS 26.2, the second major point update for iPhones since iOS 26 was rolled out in September, and there are at least 15 notable changes and improvements worth checking out. We've rounded them up below. Apple is expected to roll out iOS 26.2 to compatible devices sometime between December 8 and December 16. When the update drops, you can check Apple's servers for the ...
iPhone 14 Pro Dynamic Island

iPhone 18 Pro Leak Adds New Evidence for Under-Display Face ID

Monday December 8, 2025 4:54 am PST by
Apple is actively testing under-screen Face ID for next year's iPhone 18 Pro models using a special "spliced micro-transparent glass" window built into the display, claims a Chinese leaker. According to "Smart Pikachu," a Weibo account that has previously shared accurate supply-chain details on Chinese Android hardware, Apple is testing the special glass as a way to let the TrueDepth...
iOS 26

Apple Seeds Second iOS 26.2 Release Candidate to Developers and Public Beta Testers

Monday December 8, 2025 10:18 am PST by
Apple today seeded the second release candidate version of iOS 26.2 to developers and public beta testers, with the software coming one week after Apple seeded the first RC. The release candidate represents the final version iOS 26.2 that will be provided to the public if no further bugs are found. Registered developers and public beta testers can download the betas from the Settings app on...
iPhone 17 Pro Cosmic Orange

10 Reasons to Wait for Next Year's iPhone 18 Pro

Monday December 1, 2025 2:40 am PST by
Apple's iPhone development roadmap runs several years into the future and the company is continually working with suppliers on several successive iPhone models at the same time, which is why we often get rumored features months ahead of launch. The iPhone 18 series is no different, and we already have a good idea of what to expect for the iPhone 18 Pro and iPhone 18 Pro Max. One thing worth...
Johny Srouji

Apple's Chipmaking Chief Johny Srouji Responds to Report About Him Potentially Leaving

Monday December 8, 2025 9:23 am PST by
Apple's chipmaking chief Johny Srouji has reportedly indicated that he plans to continue working for the company for the foreseeable future. "I love my team, and I love my job at Apple, and I don't plan on leaving anytime soon," said Srouji, in a memo obtained by Bloomberg's Mark Gurman. Here is Srouji's full memo, as shared by Bloomberg:I know you've been reading all kind of rumors and...
Johny Srouji

Apple Chip Chief Johny Srouji Could Be Next to Go as Exodus Continues

Sunday December 7, 2025 10:41 am PST by
Apple's senior vice president of hardware technologies Johny Srouji could be the next leading executive to leave the company amid an alarming exodus of leading employees, Bloomberg's Mark Gurman reports. Srouji apparently recently told CEO Tim Cook that he is "seriously considering leaving" in the near future. He intends to join another company if he departs. Srouji leads Apple's chip design ...
Intel Inside iPhone Feature

Apple's Return to Intel Rumored to Extend to iPhone

Friday December 5, 2025 10:08 am PST by
Intel is expected to begin supplying some Mac and iPad chips in a few years, and the latest rumor claims the partnership might extend to the iPhone. In a research note with investment firm GF Securities this week, obtained by MacRumors, analyst Jeff Pu said he and his colleagues "now expect" Intel to reach a supply deal with Apple for at least some non-pro iPhone chips starting in 2028....
google pixel 10

Switching Between iPhone and Android Will Get Easier With New Apple and Google Collaboration

Monday December 8, 2025 11:10 am PST by
Apple and Google are teaming up to make it easier for users to switch between iPhone and Android smartphones, according to 9to5Google. There is a new Android Canary build available today that simplifies data transfer between two smartphones, and Apple is going to implement the functionality in an upcoming iOS 26 beta. Apple already has a Move to iOS app for transferring data from an Android...
Foldable iPhone 2023 Feature 1

Apple to Make More Foldable iPhones Than Expected

Tuesday December 9, 2025 9:59 am PST by
Apple has ordered 22 million OLED panels from Samsung Display for the first foldable iPhone, signaling a significantly larger production target than the display industry had previously anticipated, ET News reports. In the now-seemingly deleted report, ET News claimed that Samsung plans to mass-produce 11 million inward-folding OLED displays for Apple next year, as well as 11 million...
Apple Fitness Plus expansion hero

Apple Fitness+ Coming to 28 New Regions With Digital Voice Dubbing

Monday December 8, 2025 6:19 am PST by
Apple today announced that Fitness+ is expanding to 28 new markets on December 15 in the service's largest international rollout since launch, accompanied by new language dubbing and a K-Pop music genre. Apple Fitness+ will become available in Chile, Hong Kong, India, the Netherlands, Singapore, Taiwan, and additional regions on December 15, with Japan scheduled to follow early next year....

Top Rated Comments

Bubba Satori Avatar
131 months ago
With all the ills in the world, you have time to be this bothered about this. Consider that for a moment.
This is not illsintheworldRumors.
Consider that for a moment.
Score: 15 Votes (Like | Disagree)
Ankou_Sabat Avatar
131 months ago
Actually this response does nothing about a much larger issue on the App Store.

Take the Tweetbot issue which I had hit me. They had released a new version, Tweetbot 2.1.1, right before this issue happened on Oct 15. This updated version is incompatible with Mac OS Mavericks (10.09) so those running Mavericks were stuck with the previous version. This means that for all those running an OS older than 10.10, you're only able to run Tweetbot 1.6.2. If you go to the App Store and try to update it, or even re-download on such an older OS it explicitly tells you of the incompatibility and says that it will download the "old" version for compatibility.

That would be fine, except the old versions are still signed with the EXPIRED CERTIFICATE! So even if you follow the directions to "re-download the damaged app" it will refuse to run because the certificate signed is expired. So the only "fix" is to upgrade your OS to 10.10. Sure it can be argued to upgrade to the latest version, but there are quite a few instances where this is impossible to do and as such, Apple has just put an expiration date on older software preventing you from running it by linking it to this certificate and not providing developers a way to re-sign those submissions with an updated cert. Neither does the App Store itself provide such a facility.

So if by the current expiration date which I believe now is 2 years from now, if your computer is unable to be upgraded to current OS and the current version is unsupported on your system, then you are completely out of luck and stuck with no app that you paid for. This makes the "download old version" feature in the App Store completely flawed if they provide no way to back sign older provided version on the store front.
Score: 11 Votes (Like | Disagree)
sw1tcher Avatar
131 months ago
Software is like that. It's always just about to fall down around our ears, except usually someone is there trying to stop that from happening. Sometimes there are screw ups.
Software purchased through the MAS is like that. From what I read, people who purchased the same software directly from the developer or through other means didn't have to deal with this nonsense.

In the good ol' days, prior to the existence of the MAS, online activation, and subscription services, I'd install a program and it would just work™ until it got replaced or the computer died.
Score: 9 Votes (Like | Disagree)
gijoeinla Avatar
131 months ago
Did someone at Apple win a prize for drafting a note with the most use of "issues" in the first paragraph? How did this letter get by Apple PR?

If Apple normally does one thing well, it's strong apologies once they've completed an investigation into a problem. This letter is not that.

Yes let's tear apart the letter for next 30 posts shall we. Let's question Apples integrity over it.

Oh my god. Get over it!
Score: 7 Votes (Like | Disagree)
applerocks Avatar
131 months ago
Did someone at Apple win a prize for drafting a note with the most use of "issues" in the first paragraph? How did this letter get by Apple PR?

If Apple normally does one thing well, it's strong apologies once they've completed an investigation into a problem. This letter is not that.
Score: 5 Votes (Like | Disagree)
alphaod Avatar
131 months ago
Maybe it'll get some developers to finally update their apps.
Score: 5 Votes (Like | Disagree)