No specific info about version 12. Please visit the main page of Media Jukebox on Software Informer.
I just dumped J River Media Jukebox after using it for years. For one thing they stopped supporting and improving it. As a matter of fact, from version 12 to version 14 they even removed one of the most popular features it had, that of right clicking and updating the album art from the Internet. Also slow to get support if any unless you buy the Media Center Upgrade. I switched to it after Yahoo destroyed the Music Match Jukebox, which was the greatest. Now searching for a new one.
i love this software
Less buggy than other media players