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

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