arbtt-recover: 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/arbtt-recover - from package: arbtt

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

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