cmtk_functions.sh: 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/lib/cmtk/bin/cmtk_functions.sh - from package: cmtk

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