Real Player Downloader Unable to Download

Hello,
I used to be able to download Youtube Videos by using Real Player Downloader but since last couple of days when I try to download a Video Clip from Youtube using Real Player Downloader, it gives me a message "UNABLE TO DOWNLOAD" I am frustrated trying to troubleshoot the problem. PLEASE HELP. WHAT IS GONE WRONG? WHAT CAN I DO TO FIX THIS PROBLEM?

Thanks a lot for URGENT answer.

Regards,
SQ