POFileClean: command not found

Have You tried accessing the binary with the full path?

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/POFileClean - from package: gettext-lint

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