Did you assign the output of the VI to whatever your monitoring output is? You can do this in the tracks window or the channel VI is loaded into in the mixer or V-Rack.
When the VI player has no output the piano keys at the bottom of the player will not move (if you play from your keyboard or click on them with the mouse.) This is he best way to see if the player has an assigned and/or working output.
When the VI player has no output the piano keys at the bottom of the player will not move (if you play from your keyboard or click on them with the mouse.) This is he best way to see if the player has an assigned and/or working output.