event2vrule: 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/event2vrule - from package: flowscan

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

Error in other languages:
event2vrule: bevel nie gevind nie
event2vrule: comandă negăsită
event2vrule: comando não encontrado
event2vrule: commande introuvable
event2vrule: command not found
event2vrule: käsku ei ole
event2vrule: không tìm thấy lệnh
event2vrule: komanda nerasta
event2vrule: Kommando nicht gefunden.
event2vrule: kommandot finns inte
event2vrule: komut yok
event2vrule: nie znaleziono polecenia
event2vrule: níor aimsíodh an t-ordú
event2vrule: no se encontró la orden
event2vrule: no s'ha trobat l'ordre
event2vrule: opdracht niet gevonden
event2vrule: parancs nem található
event2vrule: perintah tidak ditemukan
event2vrule: príkaz nenájdený
event2vrule: příkaz nenalezen
event2vrule: команда не найдена
event2vrule: командата не е открита
event2vrule: 命令找不到
event2vrule: コマンドが見つかりません