sisu-html: 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/sisu-html - from package: sisu

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

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