ical2po: 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/ical2po - from package: translate-toolkit

You may install the required package with command apt-get install {package}
Error in other languages:
ical2po: bevel nie gevind nie
ical2po: comandă negăsită
ical2po: comando não encontrado
ical2po: commande introuvable
ical2po: command not found
ical2po: käsku ei ole
ical2po: không tìm thấy lệnh
ical2po: komanda nerasta
ical2po: Kommando nicht gefunden.
ical2po: kommandot finns inte
ical2po: komut yok
ical2po: nie znaleziono polecenia
ical2po: níor aimsíodh an t-ordú
ical2po: no se encontró la orden
ical2po: no s'ha trobat l'ordre
ical2po: opdracht niet gevonden
ical2po: parancs nem található
ical2po: perintah tidak ditemukan
ical2po: príkaz nenájdený
ical2po: příkaz nenalezen
ical2po: команда не найдена
ical2po: командата не е открита
ical2po: 命令找不到
ical2po: コマンドが見つかりません