Maybe this should go in Trac -- if so, I'm happy to put it there, but I'm a bit intimidated by it! :)
I set up a dev site for 3.0 beta 1 on a local server. Once I enable the multisite network and add this code, I can no longer log in:
define( 'MULTISITE', true );
define( 'VHOST', 'no' );
$base = '/';
define( 'DOMAIN_CURRENT_SITE', 'anandadev-local' );
define( 'PATH_CURRENT_SITE', '/' );
define( 'SITE_ID_CURRENT_SITE', 1 );
define( 'BLOG_ID_CURRENT_SITE', 1 );
... which is what WordPress says to add.
I did follow all the steps that WordPress asked. URL rewriting is working great, too, using ISAPI Rewrite 3. FYI, we're using IIS 6 on Windows Server 2003.
From reading other posts, a normal cause of this is an incorrect URL set for the site, but everything that way is correct.
This has happened more than once on our dev servers, so it makes me very curious!
Thanks for any help.