Exchange 2010 to 2019 problems

Hi Jeremy , thank you for the reply that worked.
Setup was almost done but than this popped up :

I tried this https://docs.microsoft.com/en-us/exchange/architecture/mailbox-servers/recreate-arbitration-mailboxes?view=exchserver-2019
Get-Mailbox "SystemMailbox{bb558c35-97f1-4cb9-8ff7-d53741dc928c}" -Arbitration | Set-Mailbox -Arbitration -UMGrammar $true -OABGen $true -GMGen $true -ClientExtensions $true -MessageTracking $true -PstProvider $true -MaxSendSize 1GB -Force3

$OABMBX = Get-Mailbox "SystemMailbox{bb558c35-97f1-4cb9-8ff7-d53741dc928c}" -Arbitration; Set-ADUser $OABMBX.SamAccountName -Add @{"msExchCapabilityIdentifiers"="40","42","43","44","47","51","52","46"}

But i cant do this 2 commands i get this error instead on the powershell :
This task does not support recipients of this type. The specified recipient office.local/Users/SystemMailbox{bb558c35-9
7f1-4cb9-8ff7-d53741dc928c} is of type UserMailbox. Please make sure that this recipient matches the required recipient
type for this task.
A positional parameter cannot be found that accepts argument 'True'.

Exchange install error :
Error:
The following error was generated when "$error.Clear();
if ($RoleIsDatacenter -ne $true -and $RoleIsDatacenterDedicated -ne $true)
{
if (Test-ExchangeServersWriteAccess -DomainController $RoleDomainController -ErrorAction SilentlyContinue)
{
$sysMbx = $null;
$name = "SystemMailbox{bb558c35-97f1-4cb9-8ff7-d53741dc928c}";
$dispName = "Microsoft Exchange";
Write-ExchangeSetupLog -Info ("Retrieving mailboxes with Name=$name.");
$mbxs = @(Get-Mailbox -Arbitration -Filter {name -eq $name} -IgnoreDefaultScope -ResultSize 1 );
if ($mbxs.Length -eq 0)
{
Write-ExchangeSetupLog -Info ("Retrieving mailbox databases on Server=$RoleFqdnOrName.");
$dbs = @(Get-MailboxDatabase -Server:$RoleFqdnOrName -DomainController $RoleDomainController);
if ($dbs.Length -ne 0)
{
Write-ExchangeSetupLog -Info ("Retrieving users with Name=$name.");
$arbUsers = @(Get-User -Filter {name -eq $name} -IgnoreDefaultScope -ResultSize 1);
if ($arbUsers.Length -ne 0)
{
Write-ExchangeSetupLog -Info ("Enabling mailbox $name.");
$sysMbx = Enable-Mailbox -Arbitration -Identity $arbUsers[0] -DisplayName $dispName -database $dbs[0].Identity;
}
}
}
else
{
if ($mbxs[0].DisplayName -ne $dispName )
{
Write-ExchangeSetupLog -Info ("Setting DisplayName=$dispName.");
Set-Mailbox -Arbitration -Identity $mbxs[0] -DisplayName $dispName -Force;
}
$sysMbx = $mbxs[0];
}

# Set the Organization Capabilities needed for this mailbox
if ($sysMbx -ne $null)
{
# We need 1 GB for uploading large OAB files to the organization mailbox
Write-ExchangeSetupLog -Info ("Setting mailbox properties.");
set-mailbox -Arbitration -identity $sysMbx -UMGrammar:$true -OABGen:$true -GMGen:$true -ClientExtensions:$true -MailRouting:$true -MessageTracking:$true -PstProvider:$true -MaxSendSize 1GB -Force;

Write-ExchangeSetupLog -Info ("Configuring offline address book(s) for this mailbox");
Get-OfflineAddressBook | where {$_.ExchangeVersion.CompareTo([Microsoft.Exchange.Data.ExchangeObjectVersion]::Exchange2012) -ge 0 -and $_.GeneratingMailbox -eq $null} | Set-OfflineAddressBook -GeneratingMailbox $sysMbx.Identity;
}
else
{
Write-ExchangeSetupLog -Info ("Cannot find arbitration mailbox with name=$name.");
}
}
else
{
Write-ExchangeSetupLog -Info "Skipping creating E15 System Mailbox because of insufficient permission."
}
}
" was run: "Microsoft.Exchange.Data.DataValidationException: Database is mandatory on UserMailbox.
at Microsoft.Exchange.Data.Directory.SystemConfiguration.TenantConfigurationCacheableItem`1.TryRunADOperation(ADOperation operation, Boolean throwExceptions)
at Microsoft.Exchange.Data.Directory.SystemConfiguration.TenantConfigurationCacheableItem`1.Initialize(OrganizationId organizationId, CacheNotificationHandler cacheNotificationHandler, Object state)
at Microsoft.Exchange.Data.Directory.SystemConfiguration.TenantConfigurationCache`1.InitializeAndAddPerTenantSettings(OrganizationId orgId, Boolean allowExceptions, TSettings& perTenantSettings, Object state)
at Microsoft.Exchange.Data.Directory.SystemConfiguration.TenantConfigurationCache`1.TryGetValue(OrganizationId orgId, Boolean allowExceptions, TSettings& perTenantSettings, Boolean& hasExpired, Object state)
at Microsoft.Exchange.Management.RecipientTasks.GetMailbox.ConvertDataObjectToPresentationObject(IConfigurable dataObject)
at Microsoft.Exchange.Configuration.Tasks.GetRecipientObjectTask`2.WriteResult(IConfigurable dataObject)
at Microsoft.Exchange.Configuration.Tasks.GetTaskBase`1.WriteResult[T](IEnumerable`1 dataObjects)
at Microsoft.Exchange.Configuration.Tasks.GetTaskBase`1.InternalProcessRecord()
at Microsoft.Exchange.Configuration.Tasks.GetObjectWithIdentityTaskBase`2.InternalProcessRecord()
at Microsoft.Exchange.Configuration.Tasks.GetRecipientObjectTask`2.InternalProcessRecord()
at Microsoft.Exchange.Management.RecipientTasks.GetRecipientWithAddressListBase`2.InternalProcessRecord()
at Microsoft.Exchange.Configuration.Tasks.Task.<ProcessRecord>b__91_1()
at Microsoft.Exchange.Configuration.Tasks.Task.InvokeRetryableFunc(String funcName, Action func, Boolean terminatePipelineIfFailed)".