altgr-ergo: command not found

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/altgr-ergo - from package: alt-ergo

You may install the required package with command apt-get install {package}

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