Name the 24 most topographically isolated mountains. The topographic isolation of a summit is the minimum great-circle distance to a point of equal elevation.
Since you also weren't able to download the files from JetPunk Data, I am going to suggest that this is an issue related to an old internet browser or maybe some security setting on your computer.
I've solved the problem! It turns out Microsoft Edge (the browser I regularly use) doesn't let me download the files that I wanted. Fortunately, I also use Mozilla Firefox and that works.