exmenen: 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/exmenen - from package: extra-xdg-menus

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