mkslapdcert: 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/mkslapdcert - from package: debian-edu-config

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