If you subscribe to the Party Tyme subscription and you only get audio, and no video then do the following.

Some symptoms that you may see are the Duration will be very large, compared to the normal 3-6 minutes for the song.  You may also experience a black screen for the Video, instead of showing the actual Karaoke song.

Do the following to fix it.

Download the Video Codec Pack from: 

Make sure that you click on where it states:

Download [K-Lite Codec Pack X.xx FULL] where X.xx is the version number. It is currently the second link from the top. Don't click on the "Standard".

Save this file to your computer and then double click on it to run it, following the on screen instructions.

Once installed, you should be able to play video files in Hoster.

Please let us know if this doesn't fix it for you.