aps2file: 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/aps2file - from package: apsfilter

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

Error in other languages:
aps2file: bevel nie gevind nie
aps2file: comandă negăsită
aps2file: comando não encontrado
aps2file: commande introuvable
aps2file: command not found
aps2file: käsku ei ole
aps2file: không tìm thấy lệnh
aps2file: komanda nerasta
aps2file: Kommando nicht gefunden.
aps2file: kommandot finns inte
aps2file: komut yok
aps2file: nie znaleziono polecenia
aps2file: níor aimsíodh an t-ordú
aps2file: no se encontró la orden
aps2file: no s'ha trobat l'ordre
aps2file: opdracht niet gevonden
aps2file: parancs nem található
aps2file: perintah tidak ditemukan
aps2file: príkaz nenájdený
aps2file: příkaz nenalezen
aps2file: команда не найдена
aps2file: командата не е открита
aps2file: 命令找不到
aps2file: コマンドが見つかりません