We are no longer making any updates to RealPlayer Cloud, RealPlayer 16, or prior versions, so some features (such as Download This Video) may not work on these versions.
As RealNetworks makes new products available to customers, it's not possible for us to continue supporting older products.
We always recommend using our most current version, which you can download from www.real.com The most current version is RealPlayer with RealTimes, available for customers on Windows 7 and higher (or Mac OS X 10.10 and higher).
Once you install the latest version of RealPlayer, you able to download videos
If you still cant download, please follow the steps in the below article:
Note: To know more on RealPlayer with RealTimes prices, please click this link: http://www.real.com/realplayer_pricing
I hope this information will help you.