The Downloading module in SS Version 4 and Video Surgeon 2 are almost 8 years old.  With Youtube constantly making changes it may, at some point stop, working as a downloader. You have a couple of options if this happens.  You can use our free, online Youtube downloader which is found here:

https://downloadsurgeon.com/online/download/

In addition, on this same site, we offer a paid product, which can download from YouTube and thousands of other sites.  There is a demo or trial version
which you can try at no cost.