arbtt-capture: 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-capture - from package: arbtt

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

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