It was noted yesterday that iOS and Mac app updates were causing apps to crash when launched. Later in the day Apple issued a statement to AllThingsD explaining that the problem had been fixed.
Apple said the problem began with a server that generated DRM code for some apps that were being downloaded and that this issue affected only a small number of users.
One of the first to notice this problem was Marco Arment, creator of Instapaper, when users commented negatively on the app. Arment said the app was stable when submitted to the App Store but became corrupted upon download. Arment took to his blog yesterday to explain what he had found. He also compiled a list of the affected apps that he discovered.
The statement issue by Apple said:
We had a temporary issue that began yesterday with a server that generated DRM code for some apps being downloaded.
The issue has been rectified and we don’t expect it to occur again. Users who experienced an issue launching an app caused by this server bug can delete the affected app and re-download it.
There you have it. Any apps that are still crashing when they are opened should be deleted and re-downloaded from the App Store.