pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-4338-20991_.ps) >>/Users/jc/w/tmp/Tune-4338-get.log 2>&1" returned status 256
http://roaringjelly.org/~jc/music/book/ERM/20991_.abc

Error exit status 256; here are some files to check:
[get.cgi V=1/1 B=0 scale=0.55 512x512 PNG]
filesizedescription
Coll_43381.log 240776 Log file, useful mostly for debugging
Coll_43382.log 513346 Log file, useful mostly for debugging
Coll_43383.log 298383 Log file, useful mostly for debugging
Coll_43384.log 970492 Log file, useful mostly for debugging
Coll_43388.log 260446 Log file, useful mostly for debugging
Form_43383.log 842 Log file, useful mostly for debugging
Form_43385.log 833 Log file, useful mostly for debugging
Form_43386.log 845 Log file, useful mostly for debugging
Form_43387.log 936 Log file, useful mostly for debugging
Tune-4338-20991_.abc 50 ABC music file with the extracted tune(s)
Tune-4338-20991_.ps 6 PostScript
Tune-4338-20991_.txt 50 Plain-text file with the extracted tune(s)
Tune-4338-get.log 3794 Log file, useful mostly for debugging
Tune-43382-get.log 5022 Log file, useful mostly for debugging
Tune-43383-get.log 5949 Log file, useful mostly for debugging
These files should be available for 24 hours.