cdfmltmask: 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/cdfmltmask - from package: cdftools

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

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