gmk_ub2-long: 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-long - from package: scotch

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

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