simpleopal: 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/simpleopal - from package: simpleopal

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