vlpatch: 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/vlpatch - from package: libvcs-lite-perl

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

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