njb-tagtr: 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/njb-tagtr - from package: libnjb-tools

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