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

Apple Logo Black

Apple Just Made Its Second-Biggest Acquisition Ever After Beats

Thursday January 29, 2026 10:07 am PST by
Apple today confirmed to Reuters that it has acquired Q.ai, an Israeli startup that is working on artificial intelligence technology for audio. Apple paid close to $2 billion for Q.ai, according to sources cited by the Financial Times. That would make this Apple's second-biggest acquisition ever, after it paid $3 billion for the popular headphone and audio brand Beats in 2014. Q.ai has...
14 inch MacBook Pro Keyboard

Apple Changes How You Order a Mac

Saturday January 31, 2026 10:51 am PST by
Apple recently updated its online store with a new ordering process for Macs, including the MacBook Air, MacBook Pro, iMac, Mac mini, Mac Studio, and Mac Pro. There used to be a handful of standard configurations available for each Mac, but now you must configure a Mac entirely from scratch on a feature-by-feature basis. In other words, ordering a new Mac now works much like ordering an...
apple unsold web store

Retail Accessories Apple Won't Sell You Now Available via New Site

Friday January 30, 2026 8:46 am PST by
A newly surfaced resale operation is seemingly offering Apple Store–exclusive display accessories to the public for the first time, potentially giving consumers access to Apple-designed hardware that the company has historically kept confined to its retail environments. Apple designs a range of premium MagSafe charging stands, display trays, and hardware systems exclusively for displays in ...
Apple Creator Studio

Apple's Next Launch is Today

Tuesday January 27, 2026 2:39 pm PST by
Update: Apple Creator Studio is now available. Apple Creator Studio launches this Wednesday, January 28. The all-in-one subscription provides access to the Final Cut Pro, Logic Pro, Pixelmator Pro, Motion, Compressor, and MainStage apps, with U.S. pricing set at $12.99 per month or $129 per year. A subscription to Apple Creator Studio also unlocks "intelligent features" and "premium...
imac video apple feature

Apple Unveils First New Products of 2026

Monday January 26, 2026 1:55 pm PST by
Apple today introduced its first two physical products of 2026: a second-generation AirTag and the Black Unity Connection Braided Solo Loop for the Apple Watch. Read our coverage of each announcement to learn more:Apple Unveils New AirTag With Longer Range, Louder Speaker, and More Apple Introduces New Black Unity Apple Watch BandBoth the new AirTag and the Black Unity Connection Braided...

Top Rated Comments

Bubba Satori Avatar
133 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
133 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
133 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
133 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
133 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
133 months ago
Maybe it'll get some developers to finally update their apps.
Score: 5 Votes (Like | Disagree)