autoclass: 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/autoclass - from package: autoclass

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