Exchange 2016 install Error: Database is mandatory on User Mailbox

Exchange 2016 install Error: Database is mandatory on User Mailbox

The following error was generated when “$error.Clear();
if ( ($server -eq $null) -and ($RoleIsDatacenter -ne $true) )
Update-RmsSharedIdentity -ServerName $RoleNetBIOSName
” was run: “Microsoft.Exchange.Data.DataValidationException: Database is mandatory on UserMailbox.
at Microsoft.Exchange.Data.Directory.ADDataSession.Save(ADObject instanceToSave, IEnumerable`1 properties, Boolean bypassValidation)
at Microsoft.Exchange.Data.Directory.Recipient.ADRecipientObjectSession.Save(ADRecipient instanceToSave)
at Microsoft.Exchange.Management.Deployment.UpdateRmsSharedIdentity.Link()
at Microsoft.Exchange.Management.Deployment.UpdateRmsSharedIdentity.InternalProcessRecord()
at Microsoft.Exchange.Configuration.Tasks.Task.b__b()
at Microsoft.Exchange.Configuration.Tasks.Task.InvokeRetryableFunc(String funcName, Action func, Boolean terminatePipelineIfFailed)”.

Resolution: The above error “Database is mandatory on UserMailbox” states that “one of the system mailbox on the server is not having a Database” so to check which system mailbox is not having database please use below command

Get-mailbox -Arbitration | Format-Table Name, ServerName, Database -Auto


As you can see ,The command will display orphand mailbox which does not have database

Also see the below command which shows system mailbox on decommissioned server ‘viral-mbx02’

[PS] C:\Windows\system32>Get-Mailbox -Arbitration |ft Name, Servername

Name ServerName

—- ———-

SystemMailbox{1f05a927-0695-4348-bb62-d2369dcb23d5} viral-mbx01

FederatedEmail.4c1f4d8b-8179-4148-93bf-00a95fa1e042 viral-mbx01

SystemMailbox{e0dc1c29-89c3-4034-b678-e6c29d823ed9} viral-mbx02

SystemMailbox{bb558c35-97f1-4cb9-8ff7-d53741dc928c} viral-mbx02

Migration.8f3e7716-2011-43e4-96b1-aba62d229136 viral-mbx02

Now we will disable all of those mailboxes which present on viral-mbx02 server since viral-mbx02 server is already decommisioned long ago.

Now to disable that mailbox use below command

Disable-Mailbox “SystemMailbox{e0dc1c29-89c3-4034-b678-e6c29d823ed9}” -Arbitration -DisableLastArbitrationMailboxAllowed

Now to remove database from server which is already decommissioned use following commands,

Get-MailboxDatabase -Server viral-mbx02

Name Server Recovery ReplicationType

—- —— ——– —————

Mailbox Database 0912423282 viral-MBX02 False None

[PS] C:\Windows\system32>Remove-MailboxDatabase “Mailbox Database 0912423282”

Following article contains more info and fix to disable arbitration mailboxes.

Exchange 2013 uninstallation fails with arbitration mailbox error



Please feel free if you have any further question and I will be happy to help

Author: admin

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