What happened with my Contacts in Outlook?

Alan from Redlands, CA

Episode 1487 (2:20:30)

https://upload.wikimedia.org/wikipedia/commons/b/b7/Google_Contacts_logo.png

Alan tried to sync his contacts in Outlook and they've disappeared. What happened? Leo says that sync is often fraught with peril because that kind of catastrophe can happen easily, especially when there are duplicates. He recommends creating a backup on Google Contacts and restore when disaster strikes.