undbx: 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/undbx - from package: undbx

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

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