RealPlayer can't play mp4 files?

johntan

I tried playing an mp4 (I think) file and this is the error message I got, "Cannot play back the file. The format is not supported."

It says, "The clip cannot be played. It contains unexpected data and may be corrupt."

I can't even use Switch to change the file type. It disallows me to do so. I tried using Windows Media Player and iTunes to play the file but to I still can't.

RealPlayer can't play mp4 files? Help!!