Help_es.jar: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/share/jfractionlab/bin/Help_es.jar - from package: jfractionlab

You may install the required package with command apt-get install {package}
Error in other languages:
Help_es.jar: bevel nie gevind nie
Help_es.jar: comandă negăsită
Help_es.jar: comando não encontrado
Help_es.jar: commande introuvable
Help_es.jar: command not found
Help_es.jar: käsku ei ole
Help_es.jar: không tìm thấy lệnh
Help_es.jar: komanda nerasta
Help_es.jar: Kommando nicht gefunden.
Help_es.jar: kommandot finns inte
Help_es.jar: komut yok
Help_es.jar: nie znaleziono polecenia
Help_es.jar: níor aimsíodh an t-ordú
Help_es.jar: no se encontró la orden
Help_es.jar: no s'ha trobat l'ordre
Help_es.jar: opdracht niet gevonden
Help_es.jar: parancs nem található
Help_es.jar: perintah tidak ditemukan
Help_es.jar: príkaz nenájdený
Help_es.jar: příkaz nenalezen
Help_es.jar: команда не найдена
Help_es.jar: командата не е открита
Help_es.jar: 命令找不到
Help_es.jar: コマンドが見つかりません