I have a free document to download with my products but now you can't add more than 1 item to the basket.
If you add a document as a 'digital download' to a product then the order quantity will always be '1' for that product. If the download is free then you can use the 'Links' tab on the product to allow the customer to download it manually. If you use the 'URL' part of the 'Advanced Link' section you may need to add the file into the 'Design | Additional Files' list to ensure it is uploaded to your site.
If you add a document as a 'digital download' to a product then the order quantity will always be '1' for that product. If the download is free then you can use the 'Links' tab on the product to allow the customer to download it manually. If you use the 'URL' part of the 'Advanced Link' section you may need to add the file into the 'Design | Additional Files' list to ensure it is uploaded to your site.