“We had a temporary issue that began yesterday with a server that generated DRM code for some apps being downloaded,” Apple said in a statement. “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.”
Marco Arment, the creator of an app called Instapaper, is being credited with the discovery of the glitch, after users who had updated to version 4.2.3 of the app complained that it crashed immediately on startup. When the issue continued to occur when users deleted and installed a clean version of the app, Arment contacted Apple.
The cause was a corrupt version of the app that was being distributed from the App Store. Apple acknowledged the problem right away, and directed app developers to contact them directly to fix any issues.