default user and passwort for first installation not working

Hello,

I installed on my Nanopi M4v2 openmediavault from this Guide (on armbian buster server 5.4). But when I try the defaultuser "admin" and the password "openmediavault" I got an error message "Incorrect username or password.".

I changed the root-password to a password without punctuation mark. And I created on armbian user with the name admin and a password, but this password isn't working too. I clear the cache from my browser and tried this on firefox and chrome.
Reinstalled armbian, but same error.

I am a linux beginner, so I don't know a lot about the permissions and error messages under linux.

And which version is the installingbash from the guide installing? 4.x or 5.x?

I hope there is a solution!

Thanks!

I found the problem. I can't create a user named "admin" under armbian. Reinstalled armbian without a 2nd user, only root and look, it is working