Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/abc/Scotland/program/20200217/JigForJune.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-3213-JigForJune.ps) >>/Users/jc/w/tmp/Tune-3213-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/abc/Scotland/program/20200217/JigForJune.abc

Error exit status 256; here are some files to check:
[P=get.cgi V=1/1 B=0 scale=0.60 512x512 PNG]
filesizedescription
Form_3213.log 758 Log file, useful mostly for debugging
Form_32132.log 744 Log file, useful mostly for debugging
Form_32136.log 738 Log file, useful mostly for debugging
Tune-3213-JigForJune.abc 0 ABC music file with the extracted tune(s)
Tune-3213-JigForJune.ps 0 PostScript
Tune-3213-get.log 0 Log file, useful mostly for debugging
Tune-32131-get.log 4402 Log file, useful mostly for debugging
Tune-32132-get.log 3056 Log file, useful mostly for debugging
Tune-32133-get.log 3130 Log file, useful mostly for debugging
These files should be available for 24 hours.