HandBrakeCLI: 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/HandBrakeCLI - from package: handbrake-cli

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

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