I keep a bunch of these apps handy and regularly updated, because there will invariably be the possibility of differing results: videos that one or another of them can reel in, where others have failed. My most effective "Go To" option overall has remained Tubedigger. However, site protocols will change from time to time, as sites make changes, apparently in an effort to thwart the workings of these video downloader apps. So this becomes a back & forth tussle, an "arms race" on their respective parts. I just had a string of download failures with TD though . . . which could turn out to be isolated cases. Here is one of them:

https://www.youtube.com/watch?v=RwSS7uuVrPU&pp=ygUQY3JpdGljYWwgZHJpbmtlcg%3D%3D

(The content creator got it wrong though: Sorry, but this wasn't the greatest Western of all time ! Just arguably in the Top 25) Anyway, my Allavsoft v. 3.28 seems to have successfully downloaded it and some of the others, while not even being the most current version of the app. If so, a good illustration of what I was saying. Despite it's report of "Download Succeeded" I'll still have to check it to confirm that, as sometimes there can be defective downloads, such as with No Sound.