I received the error "We couldn't create a new partition [Error: 0xdb6dca70]"
Also under "Windows can't be installed on this drive. (Show details)" was the message "Windows cannot be installed to this disk. The selected disk has an MBR partition table. On EFI systems, Windows can only be installed to GPT disks."
Simple really. I also needed to delete the system partition. Once I did this, I clicked on 'New' and the setup wizard automatically created the partitions required, allowing me to proceed with the installation.