I just installed this module and set it up per the instructions. I tested with youtube and get this error:

Notice: Undefined property: stdClass::$comment_count in advanced_forum_preprocess_advanced_forum_topic_header() (line 452 of /home/thepinkg/public_html/motoatx.com/sites/all/modules/advanced_forum/includes/theme.inc).

It won't post the video.

I tested with vimeo and it seems to work fine.