I've deployed a new Exchange 2013 CAS/mailbox server into our Exchange 2007 organization. I created a new mailbox database on the ex2013 server and migrated a mailbox to it without issue.
I set up the CAS server to forward requests to the newly-configured legacy domain, and everything's working fine.
But now, when trying to create another database, I get a version error:
New-MailboxDatabase -name mailboxdb2 -server ex2013 -edbfilepath F:\mailboxdb2\mailboxdb2.edb -logfolderpath G:\mailboxdb2
Property InvalidDatabaseCopiesAllowed can't be set on this object because it requires the object to have version 0.10 (14.0.100.0) or later. The object's current version is 0.1 (8.0.535.0).+ CategoryInfo : NotSpecified: (:) [New-MailboxDatabase], InvalidObjectOperationException+ FullyQualifiedErrorId : 4DEAF3C9,Microsoft.Exchange.Management.SystemConfigurationTasks.NewMailboxDatabase+ PSComputerName : ex2013.domain.tld
ADSIEdit shows that the msExchVersion attribute is set to 4535486012416 everywhere, rather than 44220983382016. I don't know if this changed after my previous, successful mailbox creation, or if it's always been an issue.
Rerunning setup /prepareschema, /preparead, /preparedomain has no effect.