Cannot access swiftriver after a new installation


I have just finished installing Swiftriver on a Ubuntu 12.04 system.

On the Swiftriver user-interface (http://localhost), I cannot log in at all.

(1) How do I log in as admin? I find no instruction on this

(2) Anytime I try to create a new account (with name, e-mail, and password), I got an error message:

Oops! Something’s wrong!
It looks like we’ve broken something on our system. Do not panic - we have been notified and we will fix it shortly.

Since I don’t have a better description of the problem other than the symptom, but I guess it could be related to some error in authentication. For instance, I found the following info in /var/www/application/logs/

2014-08-05 01:28:23 — ERROR: Authorization Failed in /var/www/modules/auth/classes/Kohana/Auth.php:92

Any help is truly appreciated.