As a RealPlayer Plus customer you will be able to burn DVD's. You can burn multiple clips on one disc up to 120 minutes per DVD, up to 60 minutes for AVCHD.
On checking, we found that you have purchased RealPlayer Plus 16. Customers who purchased RealPlayer 16 Plus continued to enjoy their Plus features at no extra charge when we released RealPlayer Cloud, in the new RealTimes these features are available only with a Premium or Unlimited subscription.
As RealNetworks makes new products available to customers, it's not possible for us to continue supporting older products like RealPlayer Cloud, RealPlayer 16 etc., If you would like to download the previous version RealPlayer Cloud, uninstall the latest version and reinstall RealPlayer Cloud/RealPlayer 16 by following this article:
Also, please let us know when you are getting this error message "Add Failed" ie., Adding clips from different location to RealPlayer Library or during adding files to burn queue.