You're supposed to generate gfwdump.bin with gfwdump.exe first, then put it on SD and run the dumper, and then extract the dumps from gfwdump.bin with gfwdump.exe.
For more details see readme.txt inside the following archive: [Only registered and activated users can see links. ].
rgn0E.bin and others are just some legacy files, they don't have to contain anything.