roff2html: 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/roff2html - from package: groff

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

Error in other languages:
roff2html: bevel nie gevind nie
roff2html: comandă negăsită
roff2html: comando não encontrado
roff2html: commande introuvable
roff2html: command not found
roff2html: käsku ei ole
roff2html: không tìm thấy lệnh
roff2html: komanda nerasta
roff2html: Kommando nicht gefunden.
roff2html: kommandot finns inte
roff2html: komut yok
roff2html: nie znaleziono polecenia
roff2html: níor aimsíodh an t-ordú
roff2html: no se encontró la orden
roff2html: no s'ha trobat l'ordre
roff2html: opdracht niet gevonden
roff2html: parancs nem található
roff2html: perintah tidak ditemukan
roff2html: príkaz nenájdený
roff2html: příkaz nenalezen
roff2html: команда не найдена
roff2html: командата не е открита
roff2html: 命令找不到
roff2html: コマンドが見つかりません