The complaint is obvious.
It’s not a bug, it’s a feature.
JS,
Check your version. Some media stuff will only run on the newer versions. People with, say, ME systems have old players that won’t play new stuff, and they can’t get the newest releases, IIRC
Ditch that piece of shit media player.
Get yourself Media Player Classic. It does basically everything WMP can do, only it’s a much smaller install, uses far fewer system resources, doesn’t try to connect to the internet all the time for updates, etc., and has never given me any trouble whatsoever.
Add the following:
ffdshow
RealAlternative
QuicktimeAlternative
and Media Player Classic will play basically any video file you can possibly think of, including .rm and .mov. It’s an absolute gem, in my opinion.