troff2html: 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/troff2html - from package: troffcvt

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

Error in other languages:
troff2html: bevel nie gevind nie
troff2html: comandă negăsită
troff2html: comando não encontrado
troff2html: commande introuvable
troff2html: command not found
troff2html: käsku ei ole
troff2html: không tìm thấy lệnh
troff2html: komanda nerasta
troff2html: Kommando nicht gefunden.
troff2html: kommandot finns inte
troff2html: komut yok
troff2html: nie znaleziono polecenia
troff2html: níor aimsíodh an t-ordú
troff2html: no se encontró la orden
troff2html: no s'ha trobat l'ordre
troff2html: opdracht niet gevonden
troff2html: parancs nem található
troff2html: perintah tidak ditemukan
troff2html: príkaz nenájdený
troff2html: příkaz nenalezen
troff2html: команда не найдена
troff2html: командата не е открита
troff2html: 命令找不到
troff2html: コマンドが見つかりません