Wp-login.php doesn't recognize admin or e-mails

Hello,

Yesterday I created a website for a client, everything went great – she was able to login with the user information I provided her. Until today, I tried to login to the site to add some pictures.

The site is https://www.hirnuvahammas.fi

When I try to login via wp-login.php, it just comes up an “Error: Wrong username!” and the username is admin. I tried to recover the password to admin’s (my) e-mail, via username or e-mail, but both times I get errors again:

– Username or e-mail is invalid
– No registered users for this e-mail

(Translations might be different, because the WP version I run is in finnish, but hopefully you get the point)

So what can I do to login to the site again, it is very urgent – thank you.