LUX.fx failed to compile

I was following a guide for using ReShade in iRacing, and it was to update the LUX.png to a LUX_dt.png
I changed the file name to the new file as directed, but fat-fingered the spelling (pmg instead of png).
Now it does not let me alter the filename when I select LUT.fx.
I've uninstalled/re-installed it a couple of times, and it continues to say the same thing.   Even tried the 'modify' option to no avail, as well as the new install option. and repair.
I keep getting the same thing and still cannot fix it..
Do I need to adjust this correction in a different file or something?

Thank you.

FIXED:
I downloaded lux.fx, replaced old corrupt one, and was able to reconfig.
Sorry to bother.