You are running a Exchange2013 DAG
DAG2013
`-Exchange2013ServerA
`-DB2013-01, DB2013-02 (passive)
`-Exchange2013ServerB
`-DB2013-02, DB2013-01 (passive)
and want to move to 2019 but you are like this
DAG2019
`-Exchange2019ServerA
`-DB2019-01
`-Exchange2019ServerB
Test-MAPIConnectivity -Server xchange2019ServerA
failes with long ROG trace, you cannot get a healthy replication or Eventlog Shows Database Errors, but the essence is:
[Microsoft.Exchange.Data.Storage.NoSupportException]: Cannot open mailbox. There is no support for this operation. Inner error[Microsoft.Mapi.MapiExceptionNoSupport]:MapiExceptionNoSupport: Unable to open message store.(hr=0x80040102, ec=-2147221246)
Please note, this post ONLY covers 0x80040102 && MapiExceptionNoSupport. Other combinations with very similar traces have different solutions!
There is not much information about this online and most of it seems to just magically work after a reboot.
The problem seems to be here:
Get-MailboxDatabaseCopyStatus |fl name,*schema*
Name : DB2019-01\Exchange2019ServerA
MinimumSupportedDatabaseSchemaVersion : 0.121
MaximumSupportedDatabaseSchemaVersion : 0.185
RequestedDatabaseSchemaVersion : 0.121
RequestedDatabaseSchemaVersion is too low. The Ex19 Server seems to be unable to run this Databases any longer.
However
Update-DatabaseSchema -Verbose -Confirm -Identity DB2019-01 -Debug
does neither return an error nor update the database.
Using ECP with ?ExchClientVer=15.2
does not create a 0.185 Version Schema.
Using New-MailboxDatabase
on the command shell does not create a 0.185 Version Schema.
Rebooting the server, restarting replication and information store does not change the situation.