Reset Password redirects to blank admin/login.php page

[webguru]

This site just went live last week. 2 days later I had a problem when my css just seemed to be non-existent. I logged into the admin and when I tried to edit a page, or add NEW content pages, I got this:

Unknown microtiny profile __admin__

Somehow, the CSS corrected itself, but I couldn't add new content pages. I had to log out and leave for a meeting. When I tried to log back in to the admin later that day the CMSMS told me that the User name or password is incorrect. This happened the morning of the initial problem and it let me reset the password through the "lost password" link.

I tried the reset password link again and it brings me to a blank page and doesn't send me a link.

I did the password reset sql command in phpmyadmin. I even created a new account there and I can't log in with that either.

In Chrome, I get this error:
Server error
500
The website encountered an error while retrieving http://www.slocarfree.org/admin/login.php. It may be down for maintenance or configured incorrectly.

I would be happy to give all the info of the site, but I can't get into the admin. I am running version 2.1.1.

Any help is greatly appreciated, as I haven't been able to access the admin and I need to hand it off to the client.

Thanks!

[webguru]

If it matters to anyone, the only way I was able to fix it was to have the hosting company do a full restore of the entire site, including the database from a restoration point when it all worked.