I searched the Wiki as well as your forum thread. I find nothing about the lack of ability to play WVC1 files. I'm running MC19, Win7-32, Nvidia FX3800, i7, 4GBram. All other BluRays and .TS files play fine. The WVC1 bluray was ripped by AnyDVD, same as with all my BluRays.
Seems I am missing a DirectShow filter???
In googling this problem I see VLC Media Player has the same issue. And there are pages saying Win7 does not include this CODEC by default.
What is JRiver's advice to solve this? I just don't want to start blindly loading 3rd party CODECS.