updated 11:17 am EDT, Thu July 5, 2012
Affected apps crashing instantly on launch
For several days the App Store has sometimes been pushing out corrupted binaries, prominent developers are complaining. Instapaper creator Marco Arment notes that affected apps will crash automatically on launch every time, even after deleting and reinstalling, so long as the broken file is hosted on the App Store. Just under two dozen apps -- including Instapaper -- are known to have been impacted, though the number may be higher. Fixed binaries should now be appearing, but still require people to delete and reinstall their malfunctioning apps.
Only some regions have been experiencing the issue. If updating through iTunes, 8324 or 8326 error messages may appear; titles from the Mac App Store may show a message saying "[App name] is damaged and can't be opened. Delete [the app] and download it again from the App Store." In the console, a possible string is "AppleFairplayTextCrypterSession::fairplayOpen() failed, error -42110."
One of the other affected apps is GoodReader, whose developer argues that the App Store may be sending out badly or partially-encrypted binaries, which target devices are simply refusing to recognize as valid. Like Instapaper, the latest GoodReader update should now be working properly. The latter's developer also suggests that the problem may just be a matter of timing; waiting a few hours after an update notification should ensure that a file is properly encrypted.