ferret_paths: 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/share/ferret-vis/bin/ferret_paths/ferret_paths - from package: ferret-vis

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

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