Hey have tried renaming the file?

First drag your XXXXX.fns file to main2raw. It then creates a XXX.raw file. You have to rename this file to FS.raw and paste it in the same folder that has Extract FS.bat and sefstools.exe. Then just run the Extract Fs.bat and click don't send at all error messages.

^^ Should work!!

Then you can open the newly created folder and browse to tpa -> preset -> system -> language for your wanted files

All the best!