pfqueue: 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/lib/debug/usr/sbin/pfqueue - from package: pfqueue-dbg
/usr/sbin/pfqueue - from package: pfqueue

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

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