First thing I'm seeing is the link. It ends with "dl=0." That link opens a dropbox page for playing the video, not the video itself.
Change that to "raw=1" and you should get the video itself like APL needs, not an HTML page.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…