ddbd: 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/ddbd - from package: gworkspace.app

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

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