djvu2hocr: 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/djvu2hocr - from package: ocrodjvu

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

Error in other languages:
djvu2hocr: bevel nie gevind nie
djvu2hocr: comandă negăsită
djvu2hocr: comando não encontrado
djvu2hocr: commande introuvable
djvu2hocr: command not found
djvu2hocr: käsku ei ole
djvu2hocr: không tìm thấy lệnh
djvu2hocr: komanda nerasta
djvu2hocr: Kommando nicht gefunden.
djvu2hocr: kommandot finns inte
djvu2hocr: komut yok
djvu2hocr: nie znaleziono polecenia
djvu2hocr: níor aimsíodh an t-ordú
djvu2hocr: no se encontró la orden
djvu2hocr: no s'ha trobat l'ordre
djvu2hocr: opdracht niet gevonden
djvu2hocr: parancs nem található
djvu2hocr: perintah tidak ditemukan
djvu2hocr: príkaz nenájdený
djvu2hocr: příkaz nenalezen
djvu2hocr: команда не найдена
djvu2hocr: командата не е открита
djvu2hocr: 命令找不到
djvu2hocr: コマンドが見つかりません