Doesn’t work for me on 2.6 either, i install, go through the setup pages, create my wp-admin password but don’t activate any of the optional parameters, log out and then try to login again but wp-admin is not found after submitting the password
I need to delete .htaccess and then i can get back in. I had to delete wp-admin on my previous attempt to get it working again. Left it off for now, hope you can get this reliable