I followed the upgrade instructions at http://doc.tikiwiki.org/tiki-index.php?page=Upgrade+1.9.x+to+2.x&bl=y
To upgrade my Tiki site.
The database upgrade scripts worked fine (both of them), so I locked the install script and tried to enter Tiki.
However, the login is not working anymore! Neither as a normal user nor as admin. After clicking on "login", I simply return to the main screen, but I am not
Any ideas what I can do to be able to login again?
Right now, my site is a "read only site"...