Windows Media Player has encountered an unknown error!

I get the message “Windows media player has encountered an unknown error” whenever i try to play HPATPOA. Does any1 know how to fix this and what it’s caused by?

Hey man, I get the same message with all media. This all happened after instaling MS plus with media player. I can use seperate players to play different media types but its more useful lauching from one for all types.