Savefrom also has a downloader extension to help you download video one by one.
Of course, you can also use it to , Facebook, and so forth.
It's easy for you to check that which video has fully downloaded and which one is still in the downloading process.
If it still can't be processed, try a different download site.
It can automatically start downloads at a set time, and shut down your computer when all done.
Batch Download: Add multiple videos to the download queue and process download simultaneously.