Follow these steps to resolve the issue of missing contacts or address book in Outlook:

1. Check Sync and Contact Availability: Make sure that your business contacts are synced to the device and available in the address book.
2. Check Folder Settings: Go to Outlook Settings, select the Folders tab, and review the folder structure.
3. Repair Outlook: If the folder settings are not properly configured, repair Outlook by running the utilities to reinstall Outlook data files.
4. Restore Contacts: If the issue persists, restore the contacts by downloading the contacts to a file and importing them into Outlook.