apsfilter: 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/share/apsfilter/bin/apsfilter - from package: apsfilter

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

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