I downloaded a completely legal file today and in trying to play it get this error message:
Anythign I as a near-illiterate from a computer standpoint can do to fix it on my end, or is there another free player I can try?
Check the file size, if it’s something like 1 KB, then whats most likely happened is that the web-server sent you a message saying it couldn’t find the file and your computer assumed that message was the file and saved it into a .rm file.
The file is 17 MB.
There used to be a dos command line utility called rmfix that would often clean up Realplayer problems.
Unfortunately, it has a bit of a learning curve to use and might not be compatible with newer Realplayer formats. You could, if you were feeling adventurous, google for it and give it a whirl. I have used it to repair a few broken Realplayer files in the past.
Personally, I eventually solved my Realplayer problems by…not using Realplayer any more. Not a great format, I’ve found. 
Anything for a Mac?