I saw a thread in Customer Service where another customer mentioned a problem downloading the PDF of this product.
I proceeded to attempt to download it myself and found that it had an obviously useless file size of 153 bytes. This does not seem to be the result of a bad update, as I myself bought this product several years ago and successfully downloaded it shortly thereafter -- and the date that this PDF was last updated is earlier than the date I bought it. So something seems to have messed up this PDF at your site.
Could you please investigate this PDF and see whether you can recover it to its former condition so that people who own this PDF can once again download it?