mkzopeinstance: 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/lib/zope2.13/bin/mkzopeinstance - from package: zope2.13

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

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