I checked for both latest version of FRD and youtube plugin. I have both.

FRD Version = 0.9u4
Plugin ID = youtube.com
Plugin Version = 2.9.21
Download link: [www.youtube.com]
Behavior: ERROR – File name not found
Behavior2: If I right click the entry and choose Open in WebBrowser it opens the correct page and plays the video.
Log file is attached.