djvused: 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 CentOS possible default full paths are:

/usr/bin/djvused - from package: djvulibre

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/djvused - from package: djvulibre-bin

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

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