vbnc2: 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/vbnc2 - from package: mono-vbnc

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

Error in other languages:
vbnc2: bevel nie gevind nie
vbnc2: comandă negăsită
vbnc2: comando não encontrado
vbnc2: commande introuvable
vbnc2: command not found
vbnc2: käsku ei ole
vbnc2: không tìm thấy lệnh
vbnc2: komanda nerasta
vbnc2: Kommando nicht gefunden.
vbnc2: kommandot finns inte
vbnc2: komut yok
vbnc2: nie znaleziono polecenia
vbnc2: níor aimsíodh an t-ordú
vbnc2: no se encontró la orden
vbnc2: no s'ha trobat l'ordre
vbnc2: opdracht niet gevonden
vbnc2: parancs nem található
vbnc2: perintah tidak ditemukan
vbnc2: príkaz nenájdený
vbnc2: příkaz nenalezen
vbnc2: команда не найдена
vbnc2: командата не е открита
vbnc2: 命令找不到
vbnc2: コマンドが見つかりません