After the urlblast runs for a while, I am not able to get the video(it keeps showing your video will be available soon) unless I restart urlblast, then video got generated right away. Then play for a while, I need to restart urlblast to get the video.
It turns out I use same location name for both wptdrive.ini and urlblast.ini. It caused the problem. After use different location name in urlblast.ini. It works fine.