Hi!

My case was not very similar with yours, but I got it fixed and I just want to share how. Perhaps my learning may help others.

I followed the step by step instructions, without realizing that I have to change the configure.php (not just make it read-only) to point to the new Admin name I assigned. Prior to doing this, I just renamed the admin and thought it would naturally point to my admin page.

After I did that, I was able to see the admin log in page and enter!