Apple: Corrupt App Update Bug Has Been Fixed
A large number of apps were affected by an upgrade crash bug on the iOS and OS X App Stores, a problem first spotted by Marco Arment, the developer of Instapaper. The story quickly gained traction, with Arment updating his blog highlighting all the apps that were stricken with the issue. Apple commented that it was looking into the problem last night, and has now confirmed that it has been fixed.
Speaking to AllThingsD, Apple outlined the cause of the problem: "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."
The issue seemed to step from the FairPlay DRM system, but everything has been resolved now. Any new updates pushed to the App Store shouldn't be affected by the issue anymore, but if you still have the crashing issue then you'll need to delete and reinstall your app.