pfsinexr: 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/pfsinexr - from package: pfstools

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

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