Yes, to upgrade Twonky you must buy a license. It’s $20.
I’ve installed the latest Twonky on 5 WD NAS’s so far. It is worth the money. It’s extremely flexible, robust, can beam to any dlna device, can aggregate from all other dlna servers on your sytem, etc. In the settings, you can specify exactly which folders you want twonky to serve and which to exclude (also which types of files). It has never crashed on me even once. I have about 100,000 song (mostly FLAC), 60,000 vidoes, and 300,000 photos. In my system Twonky scans the MBL and 3 attached USB disks. It’s about 15Tb of storage that Twonky is scanning and serving from.
I tried mediatomb and a few other media servers, but nothing is as good Twonky. Do yourself a favor and migrate to Twonky 8.03.
Here is an excellent Twonky FAQ
http://community.wd.com/t5/WD-My-Cloud/FAQ-Twonky-DLNA-Media-Server-Setup-amp-Use/td-p/858810
