0446AB3A0E4E3AEBE23500000000715A0000'". This failure can happen when MailPublicFolder objects in Exchange Online are out of sync with your Exchange deployment. You may need to rerun the script Export-MailPublicFoldersForMigration.ps1 on your Exchange server, followed by the script Import-MailPublicFoldersForMigration.ps1 on Exchange Online to update MailPublicFolder objects in Active Directory.
To locate the system public folders, open the Exchange Management Console, go to Toolbox, open the Public Folder Management Console, and then expand System Public Folders. Mail-disable any public folder that has a mail icon next to it.
Article ID: 3050726 - Last Review: 21 Dec 2016 - Revision: 1