I'm trying to move exchange mailboxes from Exchange 2010 to Exchange 2013. I have migrated all the user mailboxes and they are all working fine. When I try to migrate some system mailboxes I now get an error
"The mailbox of user Migration.firstname.lastname@example.org that is located on a server that is running version 14 can't be opened on a server that is running version 15."
I have been working using Exchange 2013 ECP and Exchange 2013 Exchange Management Shell. 2010 EMC is not working due to some error with WinRM which we'd rather not spend time looking at if we can avoid it.
I get the same error when I call Get-MigrationBatch in Exchange Management Shell.
How can I fix this error?