Curious about how do the user launches the app store if any app-store app cannot be launched?
Isn't then the app store validated with the same method?
Isn't then the app store validated with the same method?
The expired certificate was part of the receipt that gets generated for an App Store app to indicate that you have the right to use that app on your computer. Stuff that ships with the system doesn't need this and so doesn't have receipts.