gmk_ub2: 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/gmk_ub2 - from package: scotch

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

Error in other languages:
gmk_ub2: bevel nie gevind nie
gmk_ub2: comandă negăsită
gmk_ub2: comando não encontrado
gmk_ub2: commande introuvable
gmk_ub2: command not found
gmk_ub2: käsku ei ole
gmk_ub2: không tìm thấy lệnh
gmk_ub2: komanda nerasta
gmk_ub2: Kommando nicht gefunden.
gmk_ub2: kommandot finns inte
gmk_ub2: komut yok
gmk_ub2: nie znaleziono polecenia
gmk_ub2: níor aimsíodh an t-ordú
gmk_ub2: no se encontró la orden
gmk_ub2: no s'ha trobat l'ordre
gmk_ub2: opdracht niet gevonden
gmk_ub2: parancs nem található
gmk_ub2: perintah tidak ditemukan
gmk_ub2: príkaz nenájdený
gmk_ub2: příkaz nenalezen
gmk_ub2: команда не найдена
gmk_ub2: командата не е открита
gmk_ub2: 命令找不到
gmk_ub2: コマンドが見つかりません