active_interactor: 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/active_interactor - from package: vowpal-wabbit

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

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