Can't download certain youtube videos.

I'm getting an "error, can't download" when trying to download these videos:
https://www.youtube.com/watch?v=b9vwMweeAeQ
https://www.youtube.com/watch?v=NnCvGdle_K0
https://www.youtube.com/watch?v=fdsnEfiCIbA
https://www.youtube.com/watch?v=lVGZk73X2bk