after installing a b2evo site, i got this error when trying to login:

Either you have not enabled cookies or this login window has expired.

after some trial and error tests and investigation, thanks to cookie viewer from firefox addon – web developer, i found 2 identical cookies for the same domain.

perhaps a bit of explanation. the new b2evo site uses a subdomain of another b2evo site. so it looks like the new site tried to retrieve the wrong cookie information. hence login didn’t work.

the fix

edit ‘conf/_advanced.php’, change $instance_name.