It's probably sorting bugs as discussed
here.
Possible fix:
- edit file frd.sh.
- replace "java -Djava.net.preferIPv4Stack=true" with "java -Djava.net.preferIPv4Stack=true -Djava.util.Arrays.useLegacyMergeSort=true" (without quotes).
- save file frd.sh.
Run FRD by executing frd.sh.