Still no success with this. I wish there was a way to identify the file that can't be found (in the error message). It is not essential as I can brighten or darken the screen though the Intel HD Graphics Control Panel or through the monitor on-screen settings. But 'Calibrate Display Color' was another way to darken the screen display easily and my preferred option. I'm sure that the solution is out there somewhere and probably an easy one but so far no dice.