[Error Code] Can't handle conflicting folder (): Contacts [Explanation] 
If you update a contact from both Outlook and Google Apps or a separate mobile device, a conflict can occur where Google Apps Sync retains two versions of the contact. You don't lose any data when this happens—both versions of the contact are retained, and you can choose which version to keep: - See which contact has conflicting versions by opening your Sync Issues folder (in Outlook Mail, choose Go > Folder List). Note that other issues might be reported here, too. - Open the contact in Outlook. Outlook displays a message saying there has been a conflict, and lets you choose which version to keep.