wmgui: 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/wmgui - from package: wmgui

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

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