Apologies for the trouble, I have just checked again and the download button is working fine, could you please try again. I have also replied to the email you sent and sent you a direct download link in case you are still having the issue.
Could you check if you have popup disabled in the browser, if you are using any browser extensions for disabling popups or via internet security software please disable them and try again. In the mean time you can download from the link I sent.
I have re-tested, the download button is working fine at our end on Firefox and Google Chrome. You can also check at any other system or mobile that you have.