Still Lost in the Clouds
I finally figured out what happened to my files hosted on ADrive. After the majority of uploads were mysteriously made private a couple of months ago, I shared them again, thinking that they would then be available. However, when files are unshared and then shared again on ADrive, new download links are created, rendering the prior ones inactive.
As I don’t have the time to replace all those old links, my advice is to grab whatever files that are still available while you can (currently posts from 8 May 2014 to present).