Dishita's express application really works well and the support is great. I was having difficulty with some downloads not playing properly, turns out it was a codec problem that Dishita showed me how to fix from within the application. If a download fails or won't play properly, try the download again but this time change the video codec (there's a drop-down) to vp09.xx (not vp9). I didn't realize it, but you can change the codec from the "video codec" drop-down. It's very simple.

It's impossible to tell if you need to change to codec before the download is finished. The only way I can tell is that the downloaded video simply doesn't play. So try the default codec first, and if it doesn't play, download it again with a different codec. Remember that the "vp9" codec (if it's in the dropdown) does NOT work, and only the vp09.xx codec does. vp09.xx was the one that worked for all my problem videos.