Error when running Add-MailboxDatabaseCopy command: The seeding operation failed Symptoms In Microsoft Exchange Server 2019, 2016, or 2013, you run the Add-MailboxDatabaseCopy cmdlet to copy a mailbox database from one mailbox server and seed another server. After you run the cmdlet, you receive the following error message in Exchange Management Shell: The seeding operation failed. Error: An error occurred while running prerequisite checks. Error: The specified database isn't configured for replication and therefore cannot be used to perform seed operations. [Database: DB01, Server: Contoso-E16B.Contoso.com] + CategoryInfo : InvalidOperation: (DB01:String) [Add-MailboxDatabaseCopy], InvalidDbForSeedSpecifiedException + FullyQualifiedErrorId : [Server=Contoso-E16A, RequestId=5acbfa9e-76ac-497a-82c2-26cbaa31xxxx,TimeStamp=mm/dd/yy 2:22:36 PM][FailureCategory=Cmdlet-InvalidDbForSeedSpecifiedException] FFCD68C3,Microsoft.Exchange. Management.SystemConfigurationTasks.AddMailboxDatabase...