I read the previous post and you mention to fix the website so people can download the version they bought. And people asked for this three years ago. 
You not going to do that so the customer has to buy a new version if they don't the old version. Pay twice for features which don't need. People will find to download older version problem do you want people download the app from untrusted sites and when you get a reputation you selling virus? If you want to get customer trust and good reputation so treat customers as they are deserved or make a business model which suits developer and customer.

I hope you understand that without customers you only one who will use the software.