As the topic states, I migrated my multisite to production today (manual copy of files and db). Everything works except I cannot access the Network Admin (/wp-admin/my-sites.php). I keep getting bounced back to the WP login screen.
I have no issues accessing the back-end of the three sites in the Network.
I tried resetting the -adm user password in the DB, and while I can still get the site admins, I cannot access Network Admin.
This is particularly troublesome because I need to add a plugin.