Hi All
Just to confirm, the file is the digital download in your order history.
If you are not sure on how to access this, then you can do so by going into your order history, which can be found here:
https://www.auran.com/planetauran/Order_History.php
Once on the order history page, click on the order number that matches your Duchess Class purchase. On the order page, you will find a download link, click on this. This will take you to the download page, where you will find two download links (one is the mirror, and is the exact same file). Please try using the top download link first.
Once downloaded, simply run the installer. When it has finished installing, launch Content Manager, and run a 'quick database repair' (done by going to the 'file' menu, then clicking on 'quick database repair'). Once this has completed, the new/updated assets should appear within Trainz.