App Store No Longer Working in Mac OS 10.12.6 Sierra

I run Mac OS 10.12.6 on an iMac in order to continue using discontinued software. In the last week I started getting messages for some apps I purchased on the store when I only had the iMac telling me that I purchased the software on another computer and therefore in order to use it on the iMac I had to sign in with my Apple ID and password. Of course I use these apps with no problem on my Mac Studio that was purchased long after the iMac.


After proceeding to enter the requested information I receive the following message in a dialogue that appears:

"An unexpected error occurred while signing in.

The data couldn't be read because it isn't in the correct format.”


I signed out of the App Store thinking signing back in might sort the problem. Now when I try signing in I get the same error message.


I wiped the boot drive and restored it from an earlier backup. But it failed to solve the problem. I then ran the iMac from a bootable backup that was made when everything worked. But the same problem appears. Suffice to say when the iMac is booted in to a more recent OS like Big Sur I am able to run the apps and access the App Store without problems. But I need to run Sierra and want to run the apps that I paid for.


It may well be that the App Store is no longer compatible with this Mac OS. However it could also be that a particular certificate has expired and someone knows from where I can obtain a new one to get my apps working again.


I am not exactly happy that apps I purchased in good faith from the App Store are rendered inoperable because I run an older system. While it is perfectly understandable that if you run an old system you cannot expect updates, but to suddenly find that apps that worked perfectly well with the old system are now renedered useless is unacceptable. Software purchased outside of the App Store run perfectly well. Why shouldn't the same thing prevail with software purchased from the App Store? It does make one question whether it is better to purchase all software outside of the App Store if this is the end result.

iMac 27″ 5K, macOS 11.5

Posted on Feb 1, 2025 12:12 PM

Reply
Question marked as Top-ranking reply

Posted on Feb 7, 2025 3:38 PM

In of the past 6-10 hours, affected macOS systems—including Sierra and High Sierra—can sign in to the App Store again, Apple has switched on access again. I’ve personally tested this, and it’s working


Do not consider this permanent though. Use this opportunity to:

  • Open and use your legacy apps.
  • Export or back up anything critical you deem irreplaceable or cannot afford to lose.


This situation serves as a reminder: There are no guarantees of permanent access to legacy apps. Be proactive in seeking trusted alternatives or backup copies where possible to avoid being locked out in the future.

Similar questions

19 replies
Question marked as Top-ranking reply

Feb 7, 2025 3:38 PM in response to macaplan

In of the past 6-10 hours, affected macOS systems—including Sierra and High Sierra—can sign in to the App Store again, Apple has switched on access again. I’ve personally tested this, and it’s working


Do not consider this permanent though. Use this opportunity to:

  • Open and use your legacy apps.
  • Export or back up anything critical you deem irreplaceable or cannot afford to lose.


This situation serves as a reminder: There are no guarantees of permanent access to legacy apps. Be proactive in seeking trusted alternatives or backup copies where possible to avoid being locked out in the future.

Feb 1, 2025 1:08 PM in response to macaplan

I always buy outside the App Store of possible, not sure if this'll work for you but...


Go on the Apple certificate page:

Apple PKI - Apple


Download the Apple Intermediate Certificates

Apple IST CA 2 - G1 Certificate (direct download)


Double click the downloaded certificate to install it in Keychain Access.

You should see it now, in login certificates.

How I solved the Safari 13 and High Sierr… - Apple Community


Thanks to Roger Wilmut1…

how to renew certificates expired on 2011… - Apple Community

how to renew certificates expired on 2011… - Apple Community


DST Root CA X3 Certificate Expiration Problems and Fix - The Tech Journal (stephenwagner.com)


Feb 4, 2025 11:49 AM in response to macaplan

macaplan wrote:

Desktop Shelves, Yoink, Moom. Moom have kindly provided me with a standalone version after emailing them and requesting it. Desktop Shelves developer has not responded. And I have not contacted the developers of Yoink.

I have found a free older version of Yoink online:

https://en.freedownloadmanager.org/Mac-OS/Yoink.html


Could that replace your AppStore app?

Feb 2, 2025 8:20 AM in response to Thomas-M

It is disgraceful that Apple can hobble a customer's computer by rendering third party software legitimately purchased through the Apple Store useless. I have now learned my lesson that Apple is not to be trusted and the App Store avoided at all costs. I wish regulatory authorities would force the App Store to close down so that this monopoly would be rendered useless. At least then us users could go about dealing directly with developers without Apple's malign influence.

Feb 4, 2025 10:13 AM in response to Thomas-M

Thanks for this information that seems to point to the source of the problem. However it does not explain why I am unable to sign in to the Apple Store that I assume is necessary to fix the problem. And even if I could successfully sign in, this is all technically beyond my competence. I would not know what or how to fix the problem. It should be Apple's responsibility to provide a fix that ordinary users can apply.



Feb 4, 2025 10:25 AM in response to Thomas-M

That is a complete cop out. Apple has rendered inoperable software that was purchased and worked perfectly on the old system. If one had purchased the software outside of the App Store it would still be working.


It is one thing to say that a system is too old and unsupported if one needs support to do with problems intrinsic to the old system. It is another thing to render inoperable third party software that previously worked fine with the operating system. We are not slaves to Apple's quest to force us onto their new systems that require as to buy their new hardware. This needs to be publicised more broadly so that developers and users stop supporting and using the App store. Apple needs to be hit where it hurts. In the pocket. The corporate greed is breathtaking in the comtempt it shows for users as the support response demonstrates.

Feb 7, 2025 4:42 PM in response to Thomas-M

Thank you so much for alerting me. I have just managed to sign in to the App Store and I have launched the apps that were not working. But I am curious about your warning not to consider this permanent with the advice what to do. I have backups of everything. However that does not help if the apps such as the ones I could not launch require some backend access to the App Store in order to lauch. Fortunately this is not the case with many apps purchased on the App Store. Nevertheless it remains a problem if one is committed to an older OS like Sierra and its compatible applications, if some of these are rendered inoperable. The only alternative is to contact the developer and ask for a standalone version as the developers of Moom very kindly did.

Feb 7, 2025 5:50 PM in response to macaplan

I'm just pointing out that this could happen again, as there are no guarantees that the App Store will continue working indefinitely - especially for older macOS versions. Its a good reminder to seek versions from other trusted sources where available, so that if this situation happens again, you won’t lose access to software you’ve purchased through the App Store.

Some apps may be exclusively tied to the App Store, but many can be obtained from alternative sources. Additionally, running older software carries the risk that the dependencies required to run these apps may also become unavailable over time.

I’ve already reached out to developers, some have no plans to offer their software outside the App Store, others do have standalone/alternative distribution methods.

You can always sail the high seas if you trust the waters 😉.

This thread has been closed by the system or the community team. You may vote for any posts you find helpful, or search the Community for additional answers.

App Store No Longer Working in Mac OS 10.12.6 Sierra

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.