Rename wp-admin/wp-login

I renamed and activate the login page url but after that i can’t login anymore.
I only see my maintenance-page.
(Ok, for now restore with a recent backup and all works well with the default wp-admin/wp-login)

How can I activate and login with a custom login-url??
ex. http://www.polydesignbvba.be/custom_login_name

Regards,
Christophe

https://wordpress.org/plugins/all-in-one-wp-security-and-firewall/