Heyy! :D Wow I wonder about this!! I just tried it right now and it works for me! I wonder, did you download this web version and then you tried to open it in your PC? This web version is made to be played in web version, the downloable version is in "My Home" download section.
The error is because the music is not loaded but it's very weird. I've also tried the exe and it works fine :/