[KenV99]

Since you didn't link to a log my assumption is that it is the log that says 'Command Not Valid' as opposed to there being an exception/error?
I also assume that you have the above script in a file called script.sh or similar and the permissions/execute bit is properly set (i.e. you aren't root or su when you test it)?
I also assume that you have checked off to run it as a shell command (requires shell)?

I don't have any experience with ATV2 so beyond the above, I don't have any ideas.