Download Video (Not Working)

I am experiencing the same problem with most Youtube videos.
For example, this is a 54-minute video .
The Download Video tool appears to download a 1.0 Gb file, but once complete, in Finder, the file is only 1.7 Mb and plays only the first 5 seconds.
There are no other videos to download in the queue.
I am running up-to-date Mojave & Parallels Toolbox says it is up-to-date.

 

may 16th 2021 the download video will not work with rumble and bitchute now, it worked fine two days ago and now the error says the link is an incompatible file format, what's going on????

 

Hello,
what is your Parallels Toolbox version?
Could you share the link of the video please?
Also the technical data will be very helpful, please check this KB article and collect the tech report once the issue reproduced.