“You must specify the PrimaryOnly parameter” error when you try to move a primary mailbox to Exchange Online in a hybrid deployment

“You must specify the PrimaryOnly parameter” error when you try to move a primary mailbox to Exchange Online in a hybrid deployment

Got this message while trying to migrate a mailbox on-premise which had an archive in 365. We have 2010 and 2016 on premise, migrating to 365 in a hybrid model. Resolved by running the following command on the 2016 server:

1. On the 2016 server, I launched Powershell and connected to 365.

2. New-MoveRequest -Identity -Remote -RemoteHostName <2016 OWA FQDN> -RemoteCredential (Get-Credential) -BatchName -PrimaryOnly -TargetDeliveryDomain

When the credentials window comes up, enter the 2016 admin credentials.