It took me a while to do it, but it is taken care of now. I had moved the downloads to Fileserve couple of years ago to save bandwidth. However, with their changes throughout the year they are no longer reliable and causes problems to the site’s visitors. So I decided to move the downloads back to the site, with a little help from WordPress Download Manager. Let me know if you experience any issues, I tested a lot of existing links and they worked fine.