wmressel: 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/wmressel - from package: wmressel

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

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