make-ssl-cert: 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/sbin/make-ssl-cert - from package: ssl-cert

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

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