update_wdm_wmlist: 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/sbin/update_wdm_wmlist - from package: wdm

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