unable to install CU

It looks like you're hitting the file version error that’s been reported with the November 2024 Security Update (SU) for Exchange 2016/2019. This issue prevents the update from installing and can also lead to error 1603 on retry attempts.

Workaround Steps:

-Restart your Exchange server and check if services are disabled:

Get-Service -DisplayName "Microsoft exchange*" | ft DisplayName,Starttype,Status

If any services are Disabled, restore them using:

cd "C:\Program Files\Microsoft\Exchange Server\V15\Bin"

Add-PSSnapin -Name Microsoft.Exchange.Management.PowerShell.Setup -ErrorAction SilentlyContinue

.\ServiceControl.ps1 AfterPatch

-Ensure .NET Framework 4.8 is installed

Get-Hotfix

If missing, install the latest .NET 4.8 update for your Windows version (Windows Updates here).

-Manually stop Exchange services before retrying the update:

Add-PSSnapin Microsoft.Exchange.Management.PowerShell.Setup

$serviceControlPath = Join-Path $env:ExchangeInstallPath '\Bin\ServiceControl.ps1'

& $serviceControlPath -Operation 'Stop' -Roles 'LanguagePacks'

-Check for locked files using Process Explorer (Download here):

Search for Microsoft.Exchange.Data.Common.dll

If any process has it locked (e.g., antivirus), stop that process.

-Retry the SU installation and verify Exchange health after completion.

For more details, check Microsoft’s official workaround:

https://support.microsoft.com/en-us/topic/file-version-error-when-you-try-to-install-exchange-server-november-2024-su-a650da30-f8fb-469d-a449-47396cab0a15

Let us know if you’re still stuck!