Yes, you can always uninstall RealPlayer and reinstall, but before you do, why don't you try playing the video with another app, just to see whether the problem is with RealPlayer or the video itself. You can use whatever player came as the default on your system.
Also, by the way, did you know that RealPlayer has a FABULOUS Download This Video link, that allows you to download almost any video, movie or music link on the web!!!! To set it up, go to: Tools, Preferences, Download and Recording. To use it, while playing the video you want to download, just bring your cursor to the top of the video and the link will pop up.