After you use a profile file (.prf) or customization file (.msp) to configure an Outlook 2013 or Outlook 2010 profile, you cannot view your Offline Address Book (OAB), and when you try to download the Offline Address Book, you receive the following error message:
Task 'Outlook' reported error (0x8007007A): 'Unknown Error 0x8007007A'.
This issue occurs when the .prf or .msp file that is used to configure Outlook was created by using the Office Customization Tool (OCT), and the Enable offline use option was selected, but no directory path was specified to store Offline Address Book files. For more information, see customize Outlook profiles by using an Outlook Profile (PRF) file. To check the directory path of the OAB file, follow the steps in the resolution section.
You may choose to apply the corrected .prf or .msp file for Outlook to resolve this issue in a new Outlook profile. To resolve this issue in an Outlook 2013 or Outlook 2010 profile that is configured by using a PRF or MSP file without applying the corrected .prf or .msp file, follow the steps in KB3031401 0x8007007A error when you try to download an Offline Address Book because of a missing registry data .