Powershell consistently gives me some kind of eof error when it tries to download VSEdit, Wobbly, and D2VWitch.
Why it does, I don't really remember... but I ran into the exact same issue last year, on a different machine with different internet, 500 miles away, using the BITS downloader instead, meaning it's probably not platform dependant. This alternative download command (that I found somewhere on StackOverflow) works for me:
https://github.com/AlphaAtlas/vapoursynth-portable-FATPACK/commit/aee1b295f35df649ebb257f210f695e32c1785c6
Unfortunately, that command doesn't show any progress.