WordPress MU

I got plagued by the cookies problem and none of the solutions worked. Even disabling the cookies check just meant I could not log in.

After wasting 2 hours on this, hacking the wp-login.php script to death I finally discovered the problem.

WPMU does NOT like hostnames. It only likes domains.

If you set your site domain and home options to say "myserver" cookies will fail constantly. Firefox, nor IE will accept cookies from the site.

Change all references to "myserver" to "myserver.mydomain.com", delete the cache, cookies, authed sessions and all works again.

WPMU does NOT like hostnames. It only likes domains.

Unless I'm mistaken, wpmu is setup to use mydomain.tld as the basis of any cookie.

Yes... but if you have a local net with "Search domain" or "Domain suffix" then most hosts are resolved internally with just:

hostname

As opposed to:

hostname.mydomain.tld

The former would not work for me so I had to reconfigure.

It should've come up with a message about that on install.

This might even have something to do with the fact that browsers don't like those cookies to prevent security problems.