In the event eBook app does not run or when you receive this message, “App can’t be opened because it is from an unidentified developer,” you may need to adjust your security settings.

To override your security settings and open the eBook app:

  1. In the Finder, locate the app you want to open.
  2. Press the Control key, then click the app icon. Choose Open from the shortcut menu. Click Open.
  3. The eBook app is now saved as an exception to your security settings, and you will be able to open it in the future by double-clicking it.