Originally Posted by DjNDB
That error message
occurs e.g. when your internet connection breaks down during download.
It can also be caused by security software interfering with the download though.
Try downloading again, and if that doesn't work, try downloading during a clean boot. Also don't interrupt the download and don't use an additional download manager.
A gift code is used only once. When using the Gift code the game is added to your TTG Account. You can download it here
Thank you so much! It's working now!