There are unlocalized error message in the create admin-realm user page
1. In Admin Console, go to Configuration > Security > Realms > admin-realm > Manage users, and click on New button.
2. Provide any user ID and keep password filed as empty and then click on OK button.
There are unlocalized error message said, "The new password for the admin user is empty. This is not allowed when secure-admin is enabled."
Attached screen shot for your reference.