POFileChecker: 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/POFileChecker - from package: gettext-lint

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

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