Hi All, I was having an issue with http://www.ahbl.ca/wp-admin/network/ getting stuck in a redirect loop. I did some searching but did not find a good solution and finally ended up solving it myself.
Maybe this will be helpful for someone in the future :)
My setup is a multisite, with subdomains.
To debug the problem, I added the following lines to wp-admin/network/admin.php
echo "current blog domain: ".$current_blog->domain;
echo "current site domain: ".$current_site->domain;
echo "current blog path: ".$current_blog->path;
echo "current site path: ".$current_site->path;
Your current site and blog domains should be equivalent. And your current site and blog paths should also be equivalent.
In my case, blog domain was different than the site domain. I was using a http://www.example.com site domain and my blog domain was example.com. So the blog domain had to be adjusted to http://www.example.com. (WordPress is adding http here but don't add it yourself)
In your database, open the wp_blogs table.
blog_id 1, should be your main site. The value under domain should match your chosen site url. For example, the value in your wp_config.php file:
define( 'DOMAIN_CURRENT_SITE', 'www.example.com' );
The trick to tracking down this issue is to just output those values in the admin.php file, and then track down why those values are different. Remember to cleanup your admin.php file afterwords!