audisp-prelude: 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

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:

/sbin/audisp-prelude - from package: audispd-plugins

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