That's probably the reason for your difficulty. Billibilli doesn't store it's videos like You Tube does. I went through a lot of aps and plugins till I found those two I mentioned, plus mp4 downloader, that works occasionally but not all the time. Try them. Net Video Hunter and mp4 downloader also work with You Tube. When all else fails, I'll play the video as a stream in VLC and record it. I've done that a few times. Not very effective though.