langford_rf_fsynth: 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/langford_rf_fsynth - from package: langford-utils

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

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