actdiag: command not found

Have You tried accessing the binary with the full path?

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/actdiag - from package: python-actdiag

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