Hello everyone,

I have just set up Windows Server 2019 and wanted to install Exchange 2019. At step 9/13 I get an error message.
There is still an Exchange 2013 in the AD from which I would like to migrate everything.

Error message reads: "Microsoft.Exchange.Configuration.Tasks.ManagementObjectNotFoundException: The database "Mailbox Database 1434140756" was not found. Make sure that it has been entered correctly.

Here is the complete error:

Error:
The following error was generated when "$error.Clear(); 
if (!$RoleIsDatacenter -and !$RoleIsDatacenterDedicated)
{
$mailboxId = "SystemMailbox{D0E409A0-AF9B-4720-92FE-AAC869B0D201}";
$displayName = "E4E Encryption Store - Active";

$existingArbitrationMailboxes = @(Get-Mailbox -Arbitration -Filter {Name -eq $mailboxId} -IgnoreDefaultScope -ResultSize 1);
if ($existingArbitrationMailboxes.Length -eq 0)
{
$mailboxDatabase = @(get-MailboxDatabase -Server:$RoleFqdnOrName -DomainController $RoleDomainController);
if ($mailboxDatabase.Length -ne 0)
{
$mailboxUsers = @(Get-User -Filter {LastName -eq $mailboxId} -IgnoreDefaultScope -ResultSize 1);
if ($mailboxUsers.Length -ne 0)
{
$orgMailbox = Enable-Mailbox -Arbitration -Identity $mailboxUsers[0] -Database $mailboxDatabase[0].Identity;
Set-Mailbox -Arbitration `
-Identity $orgMailbox `
-RequireSenderAuthenticationEnabled $false `
-UseDatabaseQuotaDefaults $false `
-SCLDeleteEnabled $false `
-SCLJunkEnabled $false `
-SCLQuarantineEnabled $false `
-SCLRejectEnabled $false `
-HiddenFromAddressListsEnabled $true `
-DisplayName $displayName `
-Force;
}
}
}
}
" was executed: "Microsoft.Exchange.Configuration.Tasks.ManagementObjectNotFoundException: The database "Mailbox Database 1434140756" was not found. Make sure that it has been entered correctly.
for Microsoft.Exchange.Configuration.Tasks.DataAccessTask`1.GetDataObject[TObject](IIdentityParameter id, IConfigDataProvider session, ObjectId rootID, OptionalIdentityData optionalData, Func`2 notFoundError, Func`2 multipleFoundError, ExchangeErrorCategory errorCategory)
for Microsoft.Exchange.Management.RecipientTasks.GetMailboxOrSyncMailbox`1.c__DisplayClass68_0.b__0()
for Microsoft.Exchange.Data.Directory.ProvisioningCache.ProvisioningCache.TryAddAndGetGlobalDictionaryValue[T,K](Guid key, K subKey, CacheObjectGetterDelegate getter)
for Microsoft.Exchange.Management.RecipientTasks.GetMailboxOrSyncMailbox`1.SetDefaultRetentionValues(Mailbox mailbox)
for Microsoft.Exchange.Management.RecipientTasks.GetMailboxOrSyncMailbox`1.ConvertDataObjectToPresentationObject(IConfigurable dataObject)
for Microsoft.Exchange.Management.RecipientTasks.GetMailbox.ConvertDataObjectToPresentationObject(IConfigurable dataObject)
for Microsoft.Exchange.Configuration.Tasks.GetRecipientObjectTask`2.WriteResult(IConfigurable dataObject)
for Microsoft.Exchange.Configuration.Tasks.GetTaskBase`1.WriteResult[T](IEnumerable`1 dataObjects)
for Microsoft.Exchange.Configuration.Tasks.GetTaskBase`1.InternalProcessRecord()
for Microsoft.Exchange.Configuration.Tasks.GetObjectWithIdentityTaskBase`2.InternalProcessRecord()
for Microsoft.Exchange.Configuration.Tasks.GetRecipientObjectTask`2.InternalProcessRecord()
for Microsoft.Exchange.Management.RecipientTasks.GetRecipientWithAddressListBase`2.InternalProcessRecord()
for Microsoft.Exchange.Configuration.Tasks.Task.b__91_1()
for Microsoft.Exchange.Configuration.Tasks.Task.InvokeRetryableFunc(String funcName, Action func, Boolean terminatePipelineIfFailed)".

Thank you for your help.