ujguess: 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/ujguess - from package: libunicode-japanese-perl

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

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