pdfroff: 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/pdfroff - from package: groff

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

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