I checked the directory you mentioned. Under win 10, gretl 2017d produces an empty plotx.pdf file, using either octave 4.2.1 or 3.4.3. Again under win 10, gretl 1.9.12 and 1.9.92 produce empty pdf files in documents\gretl directory. So to me the big issue does not seem to be the directory, but the empty output file. I would like to remind that this script works under win 7 and older versions of gretl and octave.

Kind regards,

Andreas Zervas