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

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