Users of older versions of macOS have lost access to the Mac App Store
Mac users running macOS Mojave (10.14) and older versions are experiencing widespread problems accessing the Mac App Store. Many are unable to log in to their accounts or download previously purchased apps.
Here's What We Know
According to reports gathered by Michael Tsai, these problems appeared around 24 January 2025, when Apple changed the mechanism for processing Mac App Store receipts. Users are receiving various error messages, including "An unexpected error occurred on login" and "The data cannot be read because it is in an incorrect format".
The issues differ depending on the version of macOS. macOS Catalina (10.15) and later are stable, while Mojave allows you to browse the store but does not allow you to make new purchases or re-download previously purchased apps after the current session ends. Users of High Sierra (10.13) face missing interface elements and login errors, while macOS Sierra (10.12) completely blocks access to the Mac App Store.
The reason is probably due to changes in the receipt system, but there is no official confirmation yet. Apple recommends users to download macOS from official alternative sources, and third-party applications can be obtained directly from the developers' websites.
Apple recently introduced macOS Sequoia 15.3 with the new Genmoji feature. The macOS Sequoia 15.3 update came six weeks after the release of macOS Sequoia 15.2.
Source: MacRumors
