Update 9/24/2013 - An app update for OverDrive Media Console for iOS users is now available in the Apple App Store. This new version addresses the issues that prevented users from opening eBooks in OMC for iOS v3.0.1 after upgrading to iOS 7.
Upgrading to Apple iOS7 will cause problems for users who run the upgrade and had previously used the OverDrive Media Console app (which is used to download Library eBooks.)
If you haven't upgraded to iOS7 yet, you won't be affected. If you're unsure what version you have, you can check your version number under: Settings\General\About\Version.
When an existing OverDrive Media Console (OMC) user upgrades to iOS 7, the app will fail when trying to open a DRM-protected eBook. New or first time users of OMC are unaffected by this issue.
Until the problem is fixed, you can use the following troubleshooting guide to remedy the situation:
Troubleshooting OverDrive's mobile app on an iOS device (iPhone/iPad/iPod touch)
Please try these steps in order. Once each numbered step is completed, test your device. If it is working, you can stop! There's no need to continue on to the next step.