Question: I’ve set up my additional MSM sites, and now when I attempt to login to the original site, I am unable to do so. Logging in appears to work, but I’m not getting into the back end. What causes this, and how can I fix it?
Answer: This problem is caused by a changed setting in your config.php file:
$conf['cp_url'] = "http://secondsite.com/admin.php";
$conf['cp_url'] = "http://mainsite.com/system/";
You can edit your config.php to put back the original setting, or you can add that setting to your individual site’s path.php file.
Example:
$system_path = "./system/";
$cp_url = 'http://www.mainsite.com/admin.php';
(You can also copy the admin.php file from the /system/utilities folder into the root of your EE install.)
NOTE: Before editing your config.php and/or path.php files(s), back them up first.
In order for this fix to work, you may need to clear your site wide cookies. Information on how to do this should be in your browser’s documentation.