m17n-conv: command not found

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/bin/m17n-conv - from package: m17n-lib-bin

You may install the required package with command apt-get install {package}

Error in other languages:
m17n-conv: bevel nie gevind nie
m17n-conv: comandă negăsită
m17n-conv: comando não encontrado
m17n-conv: commande introuvable
m17n-conv: command not found
m17n-conv: käsku ei ole
m17n-conv: không tìm thấy lệnh
m17n-conv: komanda nerasta
m17n-conv: Kommando nicht gefunden.
m17n-conv: kommandot finns inte
m17n-conv: komut yok
m17n-conv: nie znaleziono polecenia
m17n-conv: níor aimsíodh an t-ordú
m17n-conv: no se encontró la orden
m17n-conv: no s'ha trobat l'ordre
m17n-conv: opdracht niet gevonden
m17n-conv: parancs nem található
m17n-conv: perintah tidak ditemukan
m17n-conv: príkaz nenájdený
m17n-conv: příkaz nenalezen
m17n-conv: команда не найдена
m17n-conv: командата не е открита
m17n-conv: 命令找不到
m17n-conv: コマンドが見つかりません