amf-to-stl: 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/amf-to-stl - from package: slic3r

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

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