Bill,
Don't know your fille location setup, but one thing for sure, that sharpening adjustment  is saved in a file with the same name as the image, but with an /flt suffix.
It  is saved with the image file in the same folder so it is found and opened when image is called.
Your error message usually indicates that there is no access to where you told QU to save. Look for a Hard drive not turned on... like that
Fred