hide_reveal_pxe_img: 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/share/drbl/bin/hide_reveal_pxe_img - from package: drbl

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