wml: 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/wml - from package: wml

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

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