html2wml: 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/bin/html2wml - from package: html2wml

You may install the required package with command apt-get install {package}
Error in other languages:
html2wml: bevel nie gevind nie
html2wml: comandă negăsită
html2wml: comando não encontrado
html2wml: commande introuvable
html2wml: command not found
html2wml: käsku ei ole
html2wml: không tìm thấy lệnh
html2wml: komanda nerasta
html2wml: Kommando nicht gefunden.
html2wml: kommandot finns inte
html2wml: komut yok
html2wml: nie znaleziono polecenia
html2wml: níor aimsíodh an t-ordú
html2wml: no se encontró la orden
html2wml: no s'ha trobat l'ordre
html2wml: opdracht niet gevonden
html2wml: parancs nem található
html2wml: perintah tidak ditemukan
html2wml: príkaz nenájdený
html2wml: příkaz nenalezen
html2wml: команда не найдена
html2wml: командата не е открита
html2wml: 命令找不到
html2wml: コマンドが見つかりません