The system files are indeed “hidden” so they cannot be accidentally deleted or erased. A factory reset would not help as that only resets your personal settings. If you can connect the palyer to your computer, you can manually re-install the firmware or format the player. In either case, any necessary files will be re-created upon re-startup.
But before doing either of these procedures, try resetting the player (if you haven’t already) by holding the power button for at least 20 secs. If that doesn’t work, try a bit longer; there have been some stubborn cases where it took over a minute of holding the power button before it reset.
