depdiagram-generate: 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/depdiagram-generate - from package: kapidox

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

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