Your download access code should be in your order invoice or email you received when you purchased the upgrade license. Open Download Assistant and enter the Cubase Upgrade license activation code you received from the Cubase upgrade purchase by clicking the 'Enter Download Access Code' button.Download the latest Steinberg Download Assistant and install on the old computer.You should now have a clean license of your original Cubase version on your USB key that you can see in the eLicenser software without any errors.Run the Online Synchronization And Maintenance task the first time you start the new installation of eLicenser, it will take a few minutes to complete.

If you have an old Cubase installation and are using a Cubase Upgrade license to build an entirely new computer, follow these steps: but hopefully this saves someone in the future. Here is what I had to do, wasn't quite as simple as hoped for.